CVE-2026-49837

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.

CVSS v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/osrg/gobgp/commit/f02ca397821f6ca182ef4eb492c3cbc459552d7c
https://github.com/osrg/gobgp/security/advisories/GHSA-gjrg-jjr3-56cm

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-10 22:16

Updated : 2026-09-16 13:42

NVD link : CVE-2026-49837

Mitre link : CVE-2026-49837

CVE.ORG link : CVE-2026-49837

JSON object : View

Products Affected

No product.

CWE

CWE-125

Out-of-bounds Read

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