low3.8
CVE-2026-71326
Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/traefik/traefik/v3 | >= 3.6.11, <= 3.6.24 | 3.6.25 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Traefik | Traefik | from 3.6.11 before 3.6.25 from 3.7.0 before 3.7.10 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-6765-c87h-8mrf
- 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