CVE-2026-71326
Fixed in a distro release EPSS <1%CVSS 2.1
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.
Products: traefik
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Go | github.com/traefik/traefik | no fix |
| Go | github.com/traefik/traefik/v2 | no fix |
| Go | github.com/traefik/traefik/v3 | 3.6.25 |
| Go | github.com/traefik/traefik/v3 | 3.7.10 |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | traefik-fips-2.11 | no fix |
| SUSE Linux Enterprise Server 16.0 | govulncheck-vulndb | 0.0.20260827T195228-160000.1.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | govulncheck-vulndb | 0.0.20260827T195228-160000.1.1 |
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260827T195228-160000.1.1 |