Vulnerability Description
Traefik versions >= v3.7.0 and <= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an Ingress carrying the nginx.ingress.kubernetes.io/auth-tls-secret annotation was named after the Ingress namespace and name. As a result, two Ingress objects sharing the same host, the same client CA secret, and the same client-authentication mode produced two distinct TLS option names for that host. Traefik treats this as a TLS options conflict and falls back to the entry point's default TLS configuration, which does not request a client certificate, so a route configured with nginx.ingress.kubernetes.io/auth-tls-verify-client: "on" becomes reachable without a client certificate. Only the v3.7 line is affected; the issue is fixed in v3.7.11.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Traefik | Traefik | >= 3.7.0, < 3.7.11 |
Related Weaknesses (CWE)
References
- https://github.com/traefik/traefik/security/advisories/GHSA-j994-9gqj-9hwqExploitMitigationPatch
- https://www.vulncheck.com/advisories/traefik-3.7-authentication-bypass-via-tls-oThird Party Advisory
FAQ
What is CVE-2026-85596?
CVE-2026-85596 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Traefik versions >= v3.7.0 and <= v3.7.10 contain an authentication bypass in the Kubernetes Ingress NGINX provider. The TLS option generated for an Ingress carrying the nginx.ingress.kubernetes.io/au...
How severe is CVE-2026-85596?
CVE-2026-85596 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-85596?
Check the references section above for vendor advisories and patch information. Affected products include: Traefik Traefik.