Traefik HTTP/3 Backend NTLM Connection Reuse

Summary Traefik's HTTP/3 request path did not initialize the connection-scoped backend transport holder that isolates connection-bound NTLM and Negotiate Kerberos authentication on the HTTP/1.1 and HTTP/2 paths. The HTTP/3 entrypoint reuses the HTTPS handler chain and reaches the same backend...

EUVD-2026-75544

Traefik is an open source HTTP reverse proxy and load balancer. From 2.11.0 until 2.11.57 and 3.7.13, the HTTP/3 entrypoint ConnContext does not call service.AddTransportOnContext, so kerberosRoundTripper uses a shared backend transport instead of a transport dedicated to each frontend connection...