CVE-2026-48491 Traefik: SNICheck ignores wildcard TLSOptions mappings, allowing domain-fronted mTLS bypass

Traefik is an HTTP reverse proxy and load balancer. From 3.7.0 until 3.7.3, there is a high severity vulnerability in Traefik's domain-fronting protection SNICheck that allows an unauthenticated client to bypass mutual TLS enforced through wildcard router TLSOptions. When a router uses a wildcard...

GHSA-5R4W-85F3-PW66 Traefik: SNICheck ignores wildcard TLSOptions mappings, allowing domain-fronted mTLS bypass

Summary There is a high severity vulnerability in Traefik's domain-fronting protection SNICheck that allows an unauthenticated client to bypass mutual TLS enforced through wildcard router TLSOptions. When a router uses a wildcard host rule such as Host.example.com with stricter TLS options for...

PT-2026-50143

Name of the Vulnerable Software and Affected Versions Traefik versions 3.7.0 through 3.7.2 Description An issue in the SNICheck domain-fronting protection allows an unauthenticated client to bypass mutual TLS mTLS enforced through wildcard router TLSOptions. When a router uses a wildcard host rul...