Traefik: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') and Incorrect Authorization

Summary There is a high-severity request-smuggling vulnerability in Traefik's handling of the HTTP/1.1 Upgrade mechanism. Since Traefik moved to unencrypted HTTP/2 with prior knowledge Go 1.24, a client-initiated Upgrade: h2c request header and its connection-specific HTTP2-Settings header were...

PT-2026-89702

Summary There is a high-severity request-smuggling vulnerability in Traefik's handling of the HTTP/1.1 Upgrade mechanism. Since Traefik moved to unencrypted HTTP/2 with prior knowledge Go 1.24, a client-initiated Upgrade: h2c request header and its connection-specific HTTP2-Settings header were...