Missing Authentication for Critical Function in Traefik - #VU153909
Published: October 7, 2026
Vulnerability details
The vulnerability allows a remote attacker to bypass authentication and source allow-list restrictions to access a protected backend.
The vulnerability exists due to missing authentication and source allow-list enforcement in the Kubernetes Ingress NGINX provider's sibling HTTP router when generating routing configuration for non-TLS entry points. A remote attacker can send an HTTP request with the Ingress host to a non-TLS entry point to bypass authentication and source allow-list restrictions to access a protected backend.
The Ingress must have the nginx.ingress.kubernetes.io/ssl-passthrough annotation set to true and access-control annotations such as auth-type with auth-secret, auth-url, or whitelist-source-range.