| Name | CVE-2026-49837 |
| 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| gobgp (PTS) | bookworm | 3.10.0-1 | vulnerable |
| trixie | 3.36.0-2 | vulnerable |
| forky, sid | 4.8.0-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| gobgp | source | (unstable) | 4.6.0-1 | | | |
Notes
[trixie] - gobgp <no-dsa> (Minor issue)
[bookworm] - gobgp <postponed> (Minor issue, OPEN capability length under-enforcement)
[bullseye] - gobgp <postponed> (Limited support)
https://github.com/osrg/gobgp/security/advisories/GHSA-gjrg-jjr3-56cm