CVE Vulnerabilities

CVE-2025-66490

Interpretation Conflict

Published: Dec 09, 2025 | Modified: Dec 11, 2025
CVSS 3.x
6.5
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
7.4 IMPORTANT
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Ubuntu

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.

Weakness

Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B’s state.

Affected Software

Name Vendor Start Version End Version
Traefik Traefik * 2.11.32 (excluding)
Traefik Traefik 3.0.0 (including) 3.6.3 (excluding)

References