{"id":"CVE-2026-4137","summary":"Incomplete Fix for CVE-2025-10279: Insecure Temporary Directory Permissions in mlflow/mlflow","details":"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.","aliases":["BIT-mlflow-2026-4137","GHSA-f2m9-wcf4-cwwx","PYSEC-2026-2655"],"modified":"2026-07-27T03:56:19.283810264Z","published":"2026-05-18T20:26:23.104Z","database_specific":{"cwe_ids":["CWE-378"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4137.json","unresolved_ranges":[{"extracted_events":[{"fixed":"3.11.0"}],"source":"AFFECTED_FIELD"}],"cna_assigner":"@huntr_ai"},"references":[{"type":"WEB","url":"https://huntr.com/bounties/648dc30b-76c7-4433-86b8-f43d926fd8d6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/4xxx/CVE-2026-4137.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-4137"},{"type":"FIX","url":"https://github.com/mlflow/mlflow/commit/1dcbb0c2fbd1f446c328830e601ca13a28219b8a"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mlflow/mlflow","events":[{"introduced":"0"},{"fixed":"1dcbb0c2fbd1f446c328830e601ca13a28219b8a"}],"database_specific":{"source":"REFERENCES"}}],"versions":["nightly","v3.0.0","v2.2.0","v1.7.0","1.0.0","v0.8.1","v0.8.0","v0.7","v0.6.0","v0.5.0","v0.4.2","v0.4.1","v0.4.0","v0.3.0","v0.2.1","v0.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-4137.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}