CVE-2026-67309

Summary

Traefik versions >= v3.7.0 and <= v3.7.7 contain a path traversal vulnerability in the Kubernetes Ingress NGINX provider's RewriteTarget middleware (generated from the nginx.ingress.kubernetes.io/rewr

Details

Traefik versions >= v3.7.0 and <= v3.7.7 contain a path traversal vulnerability in the Kubernetes Ingress NGINX provider's RewriteTarget middleware (generated from the nginx.ingress.kubernetes.io/rewrite-target annotation). When an Ingress path uses a regex that captures attacker-controlled text without requiring a path separator (e.g., path /api(.*) with rewrite target /$1), a crafted request such as /api../admin matches the public router, is rewritten to a dot-segment traversal path (/../admin), and is forwarded without post-replacement normalization validation. A backend that normalizes dot segments resolves the path to a protected endpoint (e.g., /admin) reachable only through a separate router secured with BasicAuth, DigestAuth, or ForwardAuth, resulting in route-level authentication bypass. The issue is fixed in v3.7.8.

References

• https://github.com/traefik/traefik/commit/69259c3acc9d4bdc065cb2e3b83336f7de3e7038
• https://github.com/traefik/traefik/commit/b93f02cd07b79490fb8c8f02e301a7a1ec553195
• https://github.com/traefik/traefik/security/advisories/GHSA-8rxv-jg7p-wvg3
• https://www.vulncheck.com/advisories/traefik-path-traversal-via-rewritetarget-authentication-bypass