CVE-2026-2614: Arbitrary File Read via Prompt Tag Source Validation Bypass in mlflow/mlflow

A vulnerability in the createmodelversion() 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.isprompt, which bypasses source path validation. This enables an attacker to store an arbitrary local filesystem path as the model version source. The getmodelversionartifacthandler() 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.