GHSA-3Q9R-P662-5J8M Traefik: ForwardAuth middleware leaks X-Forwarded-Port spoofing via untrusted X-Forwarded-Proto when trustForwardHeader=false

Summary There is a medium severity vulnerability in Traefik's ForwardAuth middleware. Even when configured with trustForwardHeader: false, Traefik derives the X-Forwarded-Port header sent to the authentication service from the original incoming request instead of the sanitized forwarded request. ...

CVE-2026-54764

A flaw was found in Traefik, an HTTP reverse proxy and load balancer. The ForwardAuth middleware, even when configured to not trust forwarded headers, incorrectly uses the original incoming request to determine the X-Forwarded-Port header sent to the authentication service. This allows an...

Insufficient Verification of Data Authenticity

Overview Affected versions of this package are vulnerable to Insufficient Verification of Data Authenticity in the ForwardAuth process when trustForwardHeader is set to false. An attacker can bypass port-based authorization checks by injecting a crafted X-Forwarded-Proto header over an unencrypte...