CVE-2026-65600: Traefik

Medium severity, CVSS 5.3. EPSS: 0.6% chance of exploitation in the next 30 days.

Traefik versions <= v2.11.51, >= v3.6.0 <= v3.6.22, and >= v3.7.0 <= v3.7.6 contain an authentication bypass via path traversal in the ReplacePathRegex middleware. When ReplacePathRegex is configured with a regex that captures user-controlled path segments without a mandatory path separator (e.g. regex "^/api(.*)", replacement "/$1"), the middleware forwards the replaced path to the backend without validating that it matches its normalized form. An unauthenticated remote attacker can send a crafted request (e.g. GET /api../admin) that produces an un-normalized path such as /../admin, which a backend that normalizes paths resolves to a protected route, bypassing authentication middleware. Fixed in v2.11.52, v3.6.23, and v3.7.7.

Affected products

• Traefik Traefik: before 2.11.52 (fixed in 2.11.52); from 3.6.0, before 3.6.23 (fixed in 3.6.23); from 3.7.0, before 3.7.7 (fixed in 3.7.7)

Published 2026-07-22. Last modified 2026-10-08.