{"@context":"https://openvex.dev/ns/v0.2.0","@id":"https://database.harborguard.co/cve/CVE-2026-33433/vex.json","author":"HarborGuard Database","role":"Document Creator","timestamp":"2026-06-30T03:16:46.639Z","version":1,"tooling":"HarborGuard Database (https://database.harborguard.co)","statements":[{"vulnerability":{"name":"CVE-2026-33433","@id":"https://www.cve.org/CVERecord?id=CVE-2026-33433","description":"Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.42, 3.6.11, and 3.7.0-ea.3, when `headerField` is configured with a non-canonical HTTP header name (e.g., `x-auth-user` instead of `X-Auth-User`), an authenticated attacker can inject their own canonical version of that header to impersonate any identity to the backend. The backend receives two header entries — the attacker-injected canonical one is read first, overriding Traefik's non-canonical write. Versions 2.11.42, 3"},"products":[{"@id":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*","identifiers":{"cpe23":"cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*"}}],"status":"affected","action_statement":"No fixed version is published yet; monitor the upstream advisory.","timestamp":"2026-06-30T03:16:46.639Z"}]}