CVE-2026-71326
CVE-2026-71326 · Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.6.25 and 3.7.10, Traefik's BasicAuth middleware in pkg/middlewares/auth/basic_auth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and secret, allowing an attacker who has a valid credential and the stored hash to authenticate as an unconfigured username when headerField trusts the forwarded identity. This issue is fixed in 3.6.25 and 3.7.10.
CVSS 2.1 · Low · EPSS 0.3%
- Published
- Updated
Stack: web
Affected products and versions
traefik
- Versions
- >= 3.6.11, < 3.6.25: Affected
- >= 3.7.0, < 3.7.10: Affected
No fix published
Original sources
- https://github.com/traefik/traefik/security/advisories/GHSA-6765-c87h-8mrf
- https://github.com/traefik/traefik/pull/13572
- https://github.com/traefik/traefik/commit/b5ace8eb5d6779980567f5e75efd2d9e08b7e350
- https://github.com/traefik/traefik/releases/tag/v3.6.25
- https://github.com/traefik/traefik/releases/tag/v3.7.10
- https://nvd.nist.gov/vuln/detail/CVE-2026-71326