Copyright © 2012 Red Hat, Inc. All rights reserved. Critical 2026-09-04T11:29:59 github.com/traefik/traefik: Traefik before v2.11.55 and v3.0.0 through v3.7.10 Authentication Bypass via digestAuth 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CWE-305

Traefik versions before v2.11.55 and versions v3.0.0 through v3.7.10 contain an authentication bypass vulnerability in the digestAuth middleware where unknown usernames receive an empty secret instead of rejection. Attackers can compute a valid digest response using the empty secret and arbitrary credentials to bypass authentication on any digestAuth-protected route without a valid username or password.

An authentication bypass vulnerability was discovered in Traefik's digestAuth middleware. When an incoming request contains a username that does not exist in the configured authentication store, the application fails to reject the request and instead evaluates the credential against an empty string secret. An unauthenticated remote attacker can exploit this flaw by generating a valid HTTP Digest Authentication header calculated using an empty secret and an arbitrary password, successfully bypassing authentication controls and gaining unauthorized access to routes protected by the digestAuth middleware.

A flaw was found in Traefik's digestAuth middleware (versions before v2.11.55 and v3.0.0 through v3.7.10) where requests with unknown usernames are processed using an empty secret instead of being immediately rejected. Within Red Hat environments utilizing affected Traefik components, an unauthenticated remote attacker can exploit this default state by computing a valid HTTP digest response using an empty secret and arbitrary credentials, successfully bypassing authentication on any digestAuth-protected endpoint. Disable the digestAuth middleware and transition to alternative authentication mechanisms such as basicAuth, ForwardAuth, or mTLS. Alternatively, restrict network access to digestAuth-protected routes at an upstream gateway or network firewall until patched. Red Hat OpenShift Dev Spaces Affected devspaces/traefik-rhel9 Red Hat OpenShift GitOps Not affected openshift-gitops-1/argo-rollouts-rhel8 Red Hat OpenShift GitOps Not affected openshift-gitops-1/argo-rollouts-rhel9 https://www.cve.org/CVERecord?id=CVE-2026-85595 https://nvd.nist.gov/vuln/detail/CVE-2026-85595 https://github.com/traefik/traefik/security/advisories/GHSA-5w68-77r2-r64c https://www.vulncheck.com/advisories/traefik-before-2.11.55-authentication-bypass-via-digestauth