Traefik (pronounced traffic) is an HTTP reverse proxy and load balancer. Prior to versions 2.11.25 and 3.4.1, there is a potential vulnerability in Traefik managing the requests using a PathPrefix, Path or PathRegex matcher. When Traefik is configured to route the requests to a backend using a matcher based on the path, if the URL contains a URL encoded string in its path, it’s possible to target a backend, exposed using another router, by-passing the middlewares chain. This issue has been patched in versions 2.11.25 and 3.4.1.
https://github.com/traefik/traefik/security/advisories/GHSA-vrch-868g-9jx5
https://github.com/traefik/traefik/releases/tag/v3.4.1
https://github.com/traefik/traefik/releases/tag/v2.11.25
https://github.com/traefik/traefik/commit/08d5dfee0164aa54dd44a467870042e18e8d3f00
Published: 2025-05-30
Updated: 2025-05-30
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Severity: High
Base Score: 6.3
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.00018