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AI agent vulnerability · MLflow

CVE-2026-4137: MLFlow Creates a Temporary File With Insecure Permissions

highCVSS 3.0 7.0GHSA-f2m9-wcf4-cwwx

In mlflow/mlflow versions prior to 3.11.0, the getorcreatenfstmpdir() function in mlflow/utils/fileutils.py creates temporary directories with world-writable permissions (0o777), and the createmodeldownloadingtmpdir() function in mlflow/pyfunc/init.py creates directories with group-writable permissions (0o770).

Published May 18, 2026 · Updated Sep 1, 2026

Affected packages

mlflow

Ecosystem
PyPI
Affected
>= 1.26.0, < 3.11.0
Fixed in
3.11.0
Check
pip show mlflow

Advisory details

From the GitHub Advisory Database (CC BY 4.0).

In mlflow/mlflow versions prior to 3.11.0, the get_or_create_nfs_tmp_dir() function in mlflow/utils/file_utils.py creates temporary directories with world-writable permissions (0o777), and the _create_model_downloading_tmp_dir() function in mlflow/pyfunc/__init__.py creates directories with group-writable permissions (0o770). These insecure permissions allow local attackers to tamper with model artifacts, such as cloudpickle-serialized Python objects, and achieve arbitrary code execution when the tampered artifacts are deserialized via cloudpickle.load(). This vulnerability is particularly critical in environments with shared NFS mounts, such as Databricks, where NFS is enabled by default. The issue is a continuation of the vulnerability class addressed in CVE-2025-10279, which was only partially fixed.

Credited to Chi-Song-Owen.

References

How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology

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