PYSEC-2026-2654

A vulnerability in the _create_model_version() handler of mlflow/server/handlers.py in mlflow/mlflow versions 3.9.0 and earlier allows an unauthenticated remote attacker to read arbitrary files from the server's filesystem. The issue arises when a CreateModelVersion request includes the tag mlflow.prompt.is_prompt, which bypasses source path validation. This enables an attacker to store an arbitrary local filesystem path as the model version source. The get_model_version_artifact_handler() function later uses this source to serve files without verifying the model version's prompt status, leading to a complete confidentiality compromise. This issue is fixed in version 3.10.0.