{"id":"CVE-2026-4137","aliases":["GHSA-f2m9-wcf4-cwwx","BIT-mlflow-2026-4137","PYSEC-2026-2655"],"title":"MLFlow Creates a Temporary File With Insecure Permissions ","summary":"MLFlow Creates a Temporary File With Insecure Permissions ","severity":"high","cvss":7,"cvssVector":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","vendor":"mlflow","product":"mlflow","ecosystem":"pip","affected":["mlflow < 3.11.0"],"patched":["mlflow 3.11.0"],"published":"2026-05-18","updated":"2026-07-13","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-f2m9-wcf4-cwwx","references":[{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4137"},{"url":"https://github.com/mlflow/mlflow/commit/1dcbb0c2fbd1f446c328830e601ca13a28219b8a"},{"url":"https://github.com/advisories/GHSA-4x5p-f36r-mxxr"},{"url":"https://github.com/mlflow/mlflow"},{"url":"https://huntr.com/bounties/648dc30b-76c7-4433-86b8-f43d926fd8d6"}],"tags":["osv","pip"],"epss":0.00193,"epssPercentile":0.09234,"ingestedAt":"2026-07-13T18:57:57.008Z","slug":"CVE-2026-4137","body":"## Overview\n\nIn 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.\n\n## Affected packages\n\n- `mlflow < 3.11.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `mlflow 3.11.0`","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":38.5,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}