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CVE PROGRAM SOURCE RECORD6.9 Medium

CVE-2025-66490

Traefik doesn't Prevent Path Normalization Bypass in Router + Middleware Rules

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Status
Published
Published
Updated
Assigning organization
GitHub_M

Description

Traefik is an HTTP reverse proxy and load balancer. For versions prior to 2.11.32 and 2.11.31 through 3.6.2, requests using PathPrefix, Path or PathRegex matchers can bypass path normalization. When Traefik uses path-based routing, requests containing URL-encoded restricted characters (/, \, Null, ;, ?, #) can bypass the middleware chain and reach unintended backends. For example, a request to http://mydomain.example.com/admin%2F could reach service-a without triggering my-security-middleware, bypassing security controls for the /admin/ path. This issue is fixed in versions 2.11.32 and 3.6.3.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

traefik traefik

  • github.com/traefik/traefik/v3 < 3.6.3affected
  • github.com/traefik/traefik/v2 < 2.11.32affected
  • github.com/traefik/traefik <= 1.7.34affected

References