Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approva…

cve CVE-2026-18116 1 source, 1 claim · Watch

NVD writes:
Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard "Waiting For Me" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vec… the claim

Severity: MEDIUM NVD
CVSS: 6.1 NVD
Vendor: Concrete CMS NVD
Product: Concrete CMS NVD
CWE: CWE-79 NVD

How far exploitation has got

No public code known
Proof of concept
Proof of concept, verified
A Metasploit module
Exploited in the wild
Used in ransomware campaigns

Timeline

2026-09-14

first spoke of it: Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard "Waiting For Me" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting.

NVD

Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard "Waiting For Me" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting.

What it is to other things

affects	concretecms/concrete_cms NVD
made_by	concretecms NVD

In words only, so not counted until a person confirms one:

made_by	`concrete_cms` NVD says “Concrete CMS”
affects	`concrete_cms/concrete_cms` NVD says “Concrete CMS · Concrete CMS”

Every value, with what each source said and its receipt

Property Source Said Means here

Automatable

automatable

NVD

At least one of those steps needs a person.

receipt

Source: NVD
Its words: no
Read by: field:cve.metrics.ssvcV203[].ssvcData.options[].automatable
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	no
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

CVSS

cvss

NVD

6.1

receipt

Source: NVD
Its words: 6.1
Read by: field:cve.metrics.cvssMetricV31[type=Primary].cvssData.baseScore || field:cve.metrics.cvssMetricV31[].cvssData.baseScore
Said since: 2026-09-29 09:45 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Cvss4

cvss4

NVD

7.3

receipt

Source: NVD
Its words: 7.3
Read by: field:cve.metrics.cvssMetricV40[type=Primary].cvssData.baseScore || field:cve.metrics.cvssMetricV40[].cvssData.baseScore
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	7.3
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Cvss4 vector

cvss4_vector

NVD

CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

receipt

Source: NVD
Its words: CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Read by: field:cve.metrics.cvssMetricV40[type=Primary].cvssData.vectorString || field:cve.metrics.cvssMetricV40[].cvssData.vectorString
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
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          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

CVSS vector

cvss_vector

NVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

receipt

Source: NVD
Its words: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Read by: field:cve.metrics.cvssMetricV31[type=Primary].cvssData.vectorString || field:cve.metrics.cvssMetricV31[].cvssData.vectorString
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

CWE

cwe

NVD

CWE-79

receipt

Source: NVD
Its words: CWE-79
Read by: field:cve.weaknesses[].description[].value
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	CWE-79
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Exploitation

exploitation

NVD

none

No evidence of exploitation, and no public proof of concept.

receipt

Source: NVD
Its words: none
Read by: field:cve.metrics.ssvcV203[].ssvcData.options[].exploitation
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	none
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Product

product

NVD

Concrete CMS

receipt

Source: NVD
Its words: Concrete CMS
Read by: field:cve.affected[].affectedData[].product
Said since: 2026-09-29 17:49 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-09-29 17:49 UTC	Concrete CMS
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Severity

severity

NVD

MEDIUM

From 4.0 to 6.9.

receipt

Source: NVD
Its words: MEDIUM
Read by: field:cve.metrics.cvssMetricV31[type=Primary].cvssData.baseSeverity || field:cve.metrics.cvssMetricV31[].cvssData.baseSeverity
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	MEDIUM
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

medium

Status

status

NVD

Analyzed

receipt

Source: NVD
Its words: Analyzed
Read by: field:cve.vulnStatus
Said since: 2026-09-29 09:45 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Technical impact

technical_impact

NVD

total

The attacker gains full control of the component, or all of its information.

receipt

Source: NVD
Its words: total
Read by: field:cve.metrics.ssvcV203[].ssvcData.options[].technicalImpact
Said since: 2026-10-06 12:31 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-10-06 12:31 UTC	total
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Vendor

vendor

NVD

Concrete CMS

receipt

Source: NVD
Its words: Concrete CMS
Read by: field:cve.affected[].affectedData[].vendor
Said since: 2026-09-29 17:49 UTC
Last answered: 2026-10-06 12:41 UTC
Original: open at the source

2026-09-29 17:49 UTC	Concrete CMS
2026-09-29 09:45 UTC	—

What the source handed over

{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "collectionURL": "https://github.com/concretecms/concretecms",
            "defaultStatus": "unaffected",
            "product": "Concrete CMS",
            "repo": "https://github.com/concretecms/concretecms",
            "vendor": "Concrete CMS",
            "versions": [
              {
                "lessThanOrEqual": "9.5.2",
                "status": "affected",
                "version": "8.3.0",
                "versionType": "git"
              }
            ]
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de"
      }
    ],
    "configurations": [
      {
        "nodes": [
          {
            "cpeMatch": [
              {
                "criteria": "cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*",
                "matchCriteriaId": "976DF317-4841-403C-977D-049A956D45C2",
                "versionEndExcluding": "9.5.3",
                "versionStartIncluding": "8.3.0",
                "vulnerable": true
              }
            ],
            "negate": false,
            "operator": "OR"
          }
        ]
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard \"Waiting For Me\" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting."
      }
    ],
    "id": "CVE-2026-18116",
    "lastModified": "2026-09-21T17:49:50.103",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 2.7,
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ],
      "cvssMetricV40": [
        {
          "cvssData": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "availabilityRequirement": "NOT_DEFINED",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityRequirement": "NOT_DEFINED",
            "exploitMaturity": "NOT_DEFINED",
            "integrityRequirement": "NOT_DEFINED",
            "modifiedAttackComplexity": "NOT_DEFINED",
            "modifiedAttackRequirements": "NOT_DEFINED",
            "modifiedAttackVector": "NOT_DEFINED",
            "modifiedPrivilegesRequired": "NOT_DEFINED",
            "modifiedSubAvailabilityImpact": "NOT_DEFINED",
            "modifiedSubConfidentialityImpact": "NOT_DEFINED",
            "modifiedSubIntegrityImpact": "NOT_DEFINED",
            "modifiedUserInteraction": "NOT_DEFINED",
            "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
            "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
            "modifiedVulnIntegrityImpact": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-18116",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "total"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T13:39:06.755166Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-14T23:17:15.683",
    "references": [
      {
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "tags": [
          "Broken Link"
        ],
        "url": "https://documentation.concretecms.org/developers/introduction/version-history/953-release-notes"
      }
    ],
    "sourceIdentifier": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
    "vulnStatus": "Analyzed",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-79"
          }
        ],
        "source": "ff5b8ace-8b95-4078-9743-eac1ca5451de",
        "type": "Secondary"
      }
    ]
  }
}

—

Every claim, by kind

vulnerability

zetlyn/cve-nvd · 2026-09-14

automatable no cvss 6.1 cvss4 7.3 cvss4_vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X cvss_vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N cwe CWE-79 exploitation none product Concrete CMS severity MEDIUM status Analyzed technical_impact total vendor Concrete CMS

source