CVE-2025-66490

6.5 MEDIUM
Published: December 09, 2025 Modified: December 11, 2025

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/traefik/traefik/releases/tag/v2.11.32
Source: security-advisories@github.com
Release Notes
https://github.com/traefik/traefik/releases/tag/v3.6.4
Source: security-advisories@github.com
Release Notes
https://github.com/traefik/traefik/security/advisories/GHSA-gm3x-23wp-hc2c
Source: security-advisories@github.com
Exploit Vendor Advisory
https://github.com/traefik/traefik/security/advisories/GHSA-gm3x-23wp-hc2c
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Exploit Vendor Advisory

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
6.5 / 10.0
EPSS (Exploit Probability)
0.0%
1th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

traefik