PYSEC-2026-3593 Open WebUI: Upload `metadata.knowledge_id` bypasses the knowledge-base write-access check (read-only users can add files to KB)

Open WebUI upload metadata can add files to knowledge bases without write permission Summary Open WebUI's file upload background processing trusts the client-supplied metadata.knowledgeid value and inserts a knowledgefile association before validating that the uploading user has write access to t...