---
id: CVE-2026-41642
title: >-
  github.com/osrg/gobgp: GoBGP: Denial of Service via malformed BGP UPDATE
  message (CVE-2026-41642)
summary: >-
  A flaw was found in GoBGP 4.3.0. A malformed BGP UPDATE with an unrecognized
  Path Attribute marked as well-known is not rejected cleanly, triggering a nil
  pointer dereference that crashes the GoBGP daemon. Fixed in GoBGP 4.4.0.
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-476
vendor: Red Hat
product: github.com/osrg/gobgp/v4
affected:
  - 'github.com/osrg/gobgp/v4 >= 4.3.0, < 4.4.0'
patched:
  - github.com/osrg/gobgp/v4 4.4.0
published: '2026-05-07'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T18:05:07+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41642.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41642.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-41642'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2467703'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-41642'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-41642'
  - url: 'https://github.com/osrg/gobgp/releases/tag/v4.4.0'
  - url: 'https://github.com/osrg/gobgp/security/advisories/GHSA-7235-89m6-f4px'
  - url: 'https://github.com/osrg/gobgp'
tags:
  - csaf
  - vex
  - red-hat
  - osv
  - go
epss: 0.00605
epssPercentile: 0.46732
aliases:
  - GHSA-7235-89m6-f4px
  - GO-2026-5198
ecosystem: go
ingestedAt: '2026-07-25T19:08:11.125Z'
---

## Overview

A flaw was found in GoBGP 4.3.0. A malformed BGP UPDATE with an unrecognized Path Attribute marked as well-known is not rejected cleanly, triggering a nil pointer dereference that crashes the GoBGP daemon. Fixed in GoBGP 4.4.0.

## Vendor advisories

- **Red Hat VEX** · Important · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-41642.json)

**github.com/osrg/gobgp: GoBGP: Denial of Service via malformed BGP UPDATE message** — rated Important by Red Hat. Released 2026-05-07, updated 2026-09-18.

Not affected:

- Red Hat OpenShift Container Platform 4

## Remediation

Refer to the advisory for fix availability.

## Package advisory (CVE-2026-41642)

Affected packages:

- `github.com/osrg/gobgp/v4 >= 4.3.0, < 4.4.0`

Patched in:

- `github.com/osrg/gobgp/v4 4.4.0`

Source: https://osv.dev/vulnerability/GHSA-7235-89m6-f4px