CVE-2026-45339 Open WebUI: API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-...