Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Traefik | Traefik | < 2.11.32 |
Related Weaknesses (CWE)
References
- https://github.com/traefik/traefik/releases/tag/v2.11.32Release Notes
- https://github.com/traefik/traefik/releases/tag/v3.6.4Release Notes
- https://github.com/traefik/traefik/security/advisories/GHSA-gm3x-23wp-hc2cExploitVendor Advisory
- https://github.com/traefik/traefik/security/advisories/GHSA-gm3x-23wp-hc2cExploitVendor Advisory
FAQ
What is CVE-2025-66490?
CVE-2025-66490 is a vulnerability with a CVSS score of 6.5 (MEDIUM). 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 T...
How severe is CVE-2025-66490?
CVE-2025-66490 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-66490?
Check the references section above for vendor advisories and patch information. Affected products include: Traefik Traefik.