github.com/osrg/gobgp: GoBGP: Malformed BGP OPEN message can disrupt BGP sessions

cve CVE-2026-49837 2 sources, 2 claims · Watch

Red Hat writes:
github.com/osrg/gobgp: GoBGP: Malformed BGP OPEN message can disrupt BGP sessions the claim

What it is to other things

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

affectsosrg/gobgp
NVD says “osrg · gobgp”
made_byosrg
NVD says “osrg”

What each source says

PropertySourceSaidMeans here
Cvss
cvss
conflict		NVD5.9
receipt
Source
NVD
Its words
5.9
Read by
field:cve.metrics.cvssMetricV31[].cvssData.baseScore
Said since
2026-09-29 09:45 UTC
Last answered
2026-10-04 06:13 UTC
Original
open at the source
What the source handed over
{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "product": "gobgp",
            "vendor": "osrg",
            "versions": [
              {
                "status": "affected",
                "version": "< 4.6.0"
              }
            ]
          }
        ],
        "source": "security-advisories@github.com"
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Versions prior to 4.6.0 contain a BGP OPEN capability parsing issue where several concrete capability decoders may parse data from the full remaining capability buffer instead of the slice bounded by the declared capability length, `CapLen`. A malformed BGP OPEN message can cause bytes from a following capability to be interpreted as part of the current capability. The most security-relevant case is the 4-octet AS capability, where a capability with `CapLen == 0` may cause the parser to read bytes from the following capability as the 4-octet AS value. This parsed value may later affect peer AS validation during BGP session establishment. Version 4.6.0 patches the issue."
      }
    ],
    "id": "CVE-2026-49837",
    "lastModified": "2026-09-16T13:42:46.953",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.2,
          "impactScore": 3.6,
          "source": "security-advisories@github.com",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-49837",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "partial"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T15:10:05.962553Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-10T22:16:57.507",
    "references": [
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/commit/f02ca397821f6ca182ef4eb492c3cbc459552d7c"
      },
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/security/advisories/GHSA-gjrg-jjr3-56cm"
      }
    ],
    "sourceIdentifier": "security-advisories@github.com",
    "vulnStatus": "Deferred",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-125"
          }
        ],
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  }
}
—
Cvss
cvss
conflict		Red Hat7.4
receipt
Source
Red Hat
Its words
7.4
Read by
field:cvss3_score
Said since
2026-09-29 09:44 UTC
Last answered
2026-10-04 06:13 UTC
Original
open at the source
What the source handed over
{
  "CVE": "CVE-2026-49837",
  "CWE": "CWE-125",
  "advisories": [],
  "affected_packages": [],
  "bugzilla": "2531682",
  "bugzilla_description": "github.com/osrg/gobgp: GoBGP: Malformed BGP OPEN message can disrupt BGP sessions",
  "cvss3_score": "7.4",
  "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H",
  "cvss_score": null,
  "cvss_scoring_vector": null,
  "package_state": null,
  "public_date": "2026-09-10T21:56:13Z",
  "resource_url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-49837.json",
  "severity": "important"
}
—
Cwe
cwe
Red HatCWE-125
receipt
Source
Red Hat
Its words
CWE-125
Read by
field:CWE
Said since
2026-09-29 09:44 UTC
Last answered
2026-10-04 06:13 UTC
Original
open at the source
What the source handed over
{
  "CVE": "CVE-2026-49837",
  "CWE": "CWE-125",
  "advisories": [],
  "affected_packages": [],
  "bugzilla": "2531682",
  "bugzilla_description": "github.com/osrg/gobgp: GoBGP: Malformed BGP OPEN message can disrupt BGP sessions",
  "cvss3_score": "7.4",
  "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H",
  "cvss_score": null,
  "cvss_scoring_vector": null,
  "package_state": null,
  "public_date": "2026-09-10T21:56:13Z",
  "resource_url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-49837.json",
  "severity": "important"
}
—
Product
product
NVDgobgp
receipt
Source
NVD
Its words
gobgp
Read by
field:cve.affected[].affectedData[].product
Said since
2026-09-29 17:49 UTC
Last answered
2026-10-04 06:13 UTC
Original
open at the source
2026-09-29 17:49 UTCgobgp
2026-09-29 09:45 UTC—
What the source handed over
{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "product": "gobgp",
            "vendor": "osrg",
            "versions": [
              {
                "status": "affected",
                "version": "< 4.6.0"
              }
            ]
          }
        ],
        "source": "security-advisories@github.com"
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Versions prior to 4.6.0 contain a BGP OPEN capability parsing issue where several concrete capability decoders may parse data from the full remaining capability buffer instead of the slice bounded by the declared capability length, `CapLen`. A malformed BGP OPEN message can cause bytes from a following capability to be interpreted as part of the current capability. The most security-relevant case is the 4-octet AS capability, where a capability with `CapLen == 0` may cause the parser to read bytes from the following capability as the 4-octet AS value. This parsed value may later affect peer AS validation during BGP session establishment. Version 4.6.0 patches the issue."
      }
    ],
    "id": "CVE-2026-49837",
    "lastModified": "2026-09-16T13:42:46.953",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.2,
          "impactScore": 3.6,
          "source": "security-advisories@github.com",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-49837",
            "options": [
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                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "partial"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T15:10:05.962553Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-10T22:16:57.507",
    "references": [
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/commit/f02ca397821f6ca182ef4eb492c3cbc459552d7c"
      },
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/security/advisories/GHSA-gjrg-jjr3-56cm"
      }
    ],
    "sourceIdentifier": "security-advisories@github.com",
    "vulnStatus": "Deferred",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-125"
          }
        ],
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  }
}
—
Severity
severity
Red Hatimportant
A flaw that can easily compromise confidentiality, integrity or availability.
receipt
Source
Red Hat
Its words
important
Read by
field:severity
Said since
2026-09-29 09:44 UTC
Last answered
2026-10-04 06:13 UTC
Original
open at the source
What the source handed over
{
  "CVE": "CVE-2026-49837",
  "CWE": "CWE-125",
  "advisories": [],
  "affected_packages": [],
  "bugzilla": "2531682",
  "bugzilla_description": "github.com/osrg/gobgp: GoBGP: Malformed BGP OPEN message can disrupt BGP sessions",
  "cvss3_score": "7.4",
  "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H",
  "cvss_score": null,
  "cvss_scoring_vector": null,
  "package_state": null,
  "public_date": "2026-09-10T21:56:13Z",
  "resource_url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-49837.json",
  "severity": "important"
}
high
Status
status
NVDDeferred
receipt
Source
NVD
Its words
Deferred
Read by
field:cve.vulnStatus
Said since
2026-09-29 09:45 UTC
Last answered
2026-10-04 06:13 UTC
Original
open at the source
What the source handed over
{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "product": "gobgp",
            "vendor": "osrg",
            "versions": [
              {
                "status": "affected",
                "version": "< 4.6.0"
              }
            ]
          }
        ],
        "source": "security-advisories@github.com"
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Versions prior to 4.6.0 contain a BGP OPEN capability parsing issue where several concrete capability decoders may parse data from the full remaining capability buffer instead of the slice bounded by the declared capability length, `CapLen`. A malformed BGP OPEN message can cause bytes from a following capability to be interpreted as part of the current capability. The most security-relevant case is the 4-octet AS capability, where a capability with `CapLen == 0` may cause the parser to read bytes from the following capability as the 4-octet AS value. This parsed value may later affect peer AS validation during BGP session establishment. Version 4.6.0 patches the issue."
      }
    ],
    "id": "CVE-2026-49837",
    "lastModified": "2026-09-16T13:42:46.953",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.2,
          "impactScore": 3.6,
          "source": "security-advisories@github.com",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
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            "options": [
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              },
              {
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              },
              {
                "technicalImpact": "partial"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T15:10:05.962553Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-10T22:16:57.507",
    "references": [
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/commit/f02ca397821f6ca182ef4eb492c3cbc459552d7c"
      },
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/security/advisories/GHSA-gjrg-jjr3-56cm"
      }
    ],
    "sourceIdentifier": "security-advisories@github.com",
    "vulnStatus": "Deferred",
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        "type": "Secondary"
      }
    ]
  }
}
—
Vendor
vendor
NVDosrg
receipt
Source
NVD
Its words
osrg
Read by
field:cve.affected[].affectedData[].vendor
Said since
2026-09-29 17:49 UTC
Last answered
2026-10-04 06:13 UTC
Original
open at the source
2026-09-29 17:49 UTCosrg
2026-09-29 09:45 UTC—
What the source handed over
{
  "cve": {
    "affected": [
      {
        "affectedData": [
          {
            "product": "gobgp",
            "vendor": "osrg",
            "versions": [
              {
                "status": "affected",
                "version": "< 4.6.0"
              }
            ]
          }
        ],
        "source": "security-advisories@github.com"
      }
    ],
    "cveTags": [],
    "descriptions": [
      {
        "lang": "en",
        "value": "GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Versions prior to 4.6.0 contain a BGP OPEN capability parsing issue where several concrete capability decoders may parse data from the full remaining capability buffer instead of the slice bounded by the declared capability length, `CapLen`. A malformed BGP OPEN message can cause bytes from a following capability to be interpreted as part of the current capability. The most security-relevant case is the 4-octet AS capability, where a capability with `CapLen == 0` may cause the parser to read bytes from the following capability as the 4-octet AS value. This parsed value may later affect peer AS validation during BGP session establishment. Version 4.6.0 patches the issue."
      }
    ],
    "id": "CVE-2026-49837",
    "lastModified": "2026-09-16T13:42:46.953",
    "metrics": {
      "cvssMetricV31": [
        {
          "cvssData": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
          },
          "exploitabilityScore": 2.2,
          "impactScore": 3.6,
          "source": "security-advisories@github.com",
          "type": "Secondary"
        }
      ],
      "ssvcV203": [
        {
          "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "ssvcData": {
            "id": "CVE-2026-49837",
            "options": [
              {
                "exploitation": "none"
              },
              {
                "automatable": "no"
              },
              {
                "technicalImpact": "partial"
              }
            ],
            "role": "CISA Coordinator",
            "timestamp": "2026-09-15T15:10:05.962553Z",
            "version": "2.0.3"
          }
        }
      ]
    },
    "published": "2026-09-10T22:16:57.507",
    "references": [
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/commit/f02ca397821f6ca182ef4eb492c3cbc459552d7c"
      },
      {
        "source": "security-advisories@github.com",
        "url": "https://github.com/osrg/gobgp/security/advisories/GHSA-gjrg-jjr3-56cm"
      }
    ],
    "sourceIdentifier": "security-advisories@github.com",
    "vulnStatus": "Deferred",
    "weaknesses": [
      {
        "description": [
          {
            "lang": "en",
            "value": "CWE-125"
          }
        ],
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  }
}
—

vulnerability

github.com/osrg/gobgp: GoBGP: Malformed BGP OPEN message can disrupt BGP sessions
zetlyn/cve-redhat · 2026-09-10
cvss 7.4 cwe CWE-125 severity important source
GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Versions prior to 4.6.0 contain a BGP OPEN capability parsing issue where several concrete capability decoders may parse data from the full remaining capability buffer instead of the slice bounded by the declared capability length, `CapLen`. A malformed BGP OPEN message can cause bytes from a following capability to be interpreted as part of the current capability. The most security-relevant case is the 4-octet AS capability, where a capability with `CapLen == 0` may cause the parser to read bytes from the following capability as the 4-octet AS value. This parsed value may later affect peer AS validation during BGP session establishment. Version 4.6.0 patches the issue.
zetlyn/cve-nvd · 2026-09-10
cvss 5.9 product gobgp status Deferred vendor osrg source