CVE-2026-65601

Traefik versions 3.7.0 through 3.7.6 contain a namespace confusion vulnerability in the Kubernetes Gateway API provider. When resolving HTTPRoute.spec.rules[].backendRefs[].filters[].extensionRef, Traefik used the backend Service namespace instead of the HTTPRoute namespace. A low-privileged route author holding a ReferenceGrant for a cross-namespace Service could therefore bind a Traefik Middleware from the backend namespace without a separate grant for that middleware, potentially injecting trusted reverse-proxy identity headers into downstream requests. The issue is fixed in version 3.7.7.

Score

CVSS 3.1 8.8 High

Status

Analyzed - disclosure@vulncheck.com

Published

2026-07-22

Last modified

2026-10-08

Weaknesses

CWE-863

Affected products

• Traefik (Traefik)

References

• https://github.com/traefik/traefik/security/advisories/GHSA-qq9q-x9w4-chhj
• https://github.com/traefik/traefik/commit/26c96a3935cafb473f4a5bae1886560d9aa4e4f0
• https://www.vulncheck.com/advisories/traefik-before-namespace-confusion-via-httproute-extensionref