# CVE-2026-49838

## Summary

- **CVE ID:** CVE-2026-49838
- **Severity:** MEDIUM
- **CVSS Score:** 5.9 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-129
- **Published:** Sep 10, 2026
- **Last Modified:** Sep 10, 2026

## Description

GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Prior to version 4.7.0, GoBGP accepts a zero-length AS_PATH during UPDATE decoding and later panics while validating that attribute for a confederation eBGP peer. The vulnerable path is in the BGP UPDATE validator: a malformed UPDATE that should be rejected as a malformed AS_PATH instead reaches an unchecked `p.Value[0]` access, allowing a configured confederation eBGP peer to trigger a denial of service. Version 4.7.0 patches the issue.

## Affected Products

- osrg — gobgp (< 4.7.0)

## References

- [CNA](https://github.com/osrg/gobgp/security/advisories/GHSA-frrj-87jh-2772)
- [CNA](https://github.com/osrg/gobgp/commit/4a319a6c25630fb3cdbda3e9ccfe56e702bdaaa0)

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._