CVE-2026-88010
CVE-2026-88010 · Traefik: BasicAuth singleflight coalescing reintroduces an unauthenticated username-enumeration timing oracle
This page contains facts from public vulnerability sources. Check the original advisory before updating.
Traefik is an open source HTTP reverse proxy and load balancer. From 3.6.11 until 3.7.13, checkPassword in pkg/middlewares/auth/basic_auth.go constructs the BasicAuth singleflight key from the submitted password and stored secret. Concurrent requests for absent usernames therefore coalesce on one key while configured usernames perform separate password hashes, creating an unauthenticated timing discrepancy that reveals whether a username exists. Sequential checks remain cost-equalized, Traefik v2 and Digest authentication are not affected, and the issue does not disclose credentials or bypass authentication. This issue is fixed in version 3.7.13.
CVSS 6.3 · Medium · EPSS 0.7%
- Published
- Updated
Stack: web
Affected products and versions
traefik
- Versions
- >= 3.6.11, < 3.7.13: Affected
No fix published
Original sources
- https://github.com/traefik/traefik/security/advisories/GHSA-8fcf-v89g-xpg6
- https://github.com/traefik/traefik/pull/13816
- https://github.com/traefik/traefik/commit/ddc1bf4660b85fd61fafdd821eb8216fb1a0b130
- https://github.com/traefik/traefik/releases/tag/v3.7.13
- https://nvd.nist.gov/vuln/detail/CVE-2026-88010