Description
Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a high severity authentication bypass vulnerability in Traefik's StripPrefixRegex middleware when used in combination with ForwardAuth, BasicAuth, or DigestAuth. The middleware matches the regex against the decoded URL path but uses the resulting byte length to slice the percent-encoded raw path. When a dot (or multiple dots) appears in the prefix portion of the URL, the raw path after stripping becomes a dot-segment (e.g. /./admin/secret). ForwardAuth receives this dot-segment path in X-Forwarded-Uri, which does not match the protected path patterns and therefore allows the request through. The backend then normalizes the dot-segment to the real path per RFC 3986 and serves the protected content An unauthenticated attacker can exploit this against any backend that performs dot-segment normalization. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
INFO
Published Date :
2026-04-30T20:38:21.969Z
Last Modified :
2026-05-01T14:54:06.078Z
Source :
GitHub_M
AFFECTED PRODUCTS
The following products are affected by CVE-2026-40912 vulnerability.
| Vendors | Products |
|---|---|
| Traefik |
|
REFERENCES
Here, you will find a curated list of external links that provide in-depth information to CVE-2026-40912.
