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CVE-2025-66490

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

Description (CNA)

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 (CNA)

Vendor / productVersions
traefik / traefikaffected github.com/traefik/traefik/v3 < 3.6.3; affected github.com/traefik/traefik/v2 < 2.11.32; affected github.com/traefik/traefik <= 1.7.34

CWE

CWE-436

References

ADP enrichment

CISA-ADP

No English description supplied.