CVE-2026-71326
LowCVSS 2.1Exploitation Probability (EPSS)
Low risk28th percentile - higher than 28% of all known CVEs
Summary
Traefik from 3.6.11 to 3.6.25 and 3.7.10 has a vulnerability in BasicAuth middleware allowing an attacker with valid credentials and hash to authenticate as an unconfigured username.
Risk Assessment
Risk of unauthorized access to BasicAuth-protected applications when attacker knows password hash.
Recommendation
Upgrade Traefik to 3.6.25 or 3.7.10.
Original NVD description (English source)
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.