Skip to content
CVE PROGRAM SOURCE RECORD5.9 Medium

CVE-2026-49837

GoBGP: BGP OPEN capability parser may read capability values outside declared CapLen boundaries

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

osrg gobgp

  • < 4.6.0affected

References