MLflow: Unauthenticated full-read SSRF in webhook delivery: _validate_webhook_url bypassed via unvalidated HTTP redirects (and DNS rebinding)

Summary The default MLflow Tracking Server mlflow server, no authentication, default SQLite backend exposes the model-registry webhooks API unauthenticated, including a synchronous POST /api/2.0/mlflow/webhooks/id/test endpoint that returns the upstream response status and body to the caller. The...