Traefik (pronounced traffic) is an HTTP reverse proxy and load balancer. In versions prior to 2.11.24, 3.3.6, and 3.4.0-rc2. 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 /../ 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 2.11.24, 3.3.6, and 3.4.0-rc2. A workaround involves adding a `PathRegexp` rule to the matcher to prevent matching a route with a `/../` in the path.
https://github.com/traefik/traefik/security/advisories/GHSA-6p68-w45g-48j7
https://github.com/traefik/traefik/releases/tag/v3.4.0-rc2
https://github.com/traefik/traefik/releases/tag/v3.3.6
Published: 2025-04-21
Updated: 2025-04-23
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: 8.8
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Severity: High