CVE-2026-71326: Traefik

Low severity, CVSS 3.8. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• Traefik Traefik: from 3.6.11, before 3.6.25 (fixed in 3.6.25); from 3.7.0, before 3.7.10 (fixed in 3.7.10)

Published 2026-08-06. Last modified 2026-09-16.