Traefik: BasicAuth singleflight coalescing reintroduces an unauthenticated username-enumeration timing oracle

Summary Traefik's BasicAuth middleware coalesces concurrent credential checks through a singleflight.Group to avoid hashing the same password many times at once. Since v3.6.11 the deduplication key was built from the submitted password plus the stored secret, so it depended on server state: a...

CVE-2026-88010

Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basicauth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one...

CVE-2026-88010

Traefik (open source HTTP reverse proxy and load balancer) versions 3.6.11 through before 3.7.13 contain an unauthenticated username-enumeration timing oracle in the BasicAuth middleware. The checkPassword function in pkg/middlewares/auth/basic_auth.go constructs the singleflight key from the sub...

CVE-2026-88010 Traefik: BasicAuth singleflight coalescing reintroduces an unauthenticated username-enumeration timing oracle

Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basicauth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one...

EUVD-2026-84532

Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basicauth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one...

CVE-2026-88010 Traefik: BasicAuth singleflight coalescing reintroduces an unauthenticated username-enumeration timing oracle

Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basicauth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one...

SUSE CVE-2026-71326

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

GO-2026-6204 Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing in github.com/traefik/traefik

Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing in github.com/traefik/traefik...

CVE-2026-71326

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

GHSA-6765-C87H-8MRF Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing

Summary There is a low severity vulnerability in Traefik's BasicAuth middleware. Concurrent password verifications are deduplicated through a singleflight group whose key was the delimiter-free concatenation of the submitted password and the stored secret, so a request carrying an unconfigured...

Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing

Summary There is a low severity vulnerability in Traefik's BasicAuth middleware. Concurrent password verifications are deduplicated through a singleflight group whose key was the delimiter-free concatenation of the submitted password and the stored secret, so a request carrying an unconfigured...

CVE-2026-71326

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

CVE-2026-71326

CVE-2026-71326 affects Traefik’s BasicAuth middleware (pkg/middlewares/auth/basic_auth.go) in 3.6.11–3.6.25 and 3.7.10. The vulnerability arises from deduplicating concurrent password checks using a singleflight key built from the delimiter-free concatenation of password and secret, enabling an a...

CVE-2026-71326

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

CVE-2026-71326 Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

EUVD-2026-54297

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

CVE-2026-71326 Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

CVE-2026-71326 Traefik: BasicAuth singleflight key collision allows authenticated identity spoofing

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...

CVE-2026-71326: Improper Authentication

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/basicauth.go deduplicates concurrent password checks with a singleflight key built from the delimiter-free concatenation of password and...