CVE-2025-66490
Traefik is an HTTP reverse proxy and load balancer.
Published Dec 9, 2025 · updated Oct 14, 2026 · traefik traefik
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.
Timeline
Detection, updates, and resolution for this record.
Dec 9, 2025 · NIST NVD
Detected
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 htt
Oct 14, 2026 · NIST NVD
Updated
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 htt
Affected
- cpe traefik/traefikversion unspecified
Sources
- CVE.orgCVE-2025-66490
Official CVE identifier
cve.org - FIRST EPSSCVE-2025-66490
30-day exploitation probability 0.4%
first.org - NIST NVDCVE-2025-66490
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 chara
nvd.nist.gov