id: PYSEC-2026-2655
published: "2026-07-13T15:19:09.106875Z"
modified: "2026-07-13T16:04:53.753348Z"
aliases:
- CVE-2026-4137
- GHSA-f2m9-wcf4-cwwx
summary: "MLFlow Creates a Temporary File With Insecure Permissions "
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.
affected:
- package:
    name: mlflow
    ecosystem: PyPI
    purl: pkg:pypi/mlflow
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 3.11.0
  versions:
  - 0.0.1
  - 0.1.0
  - 0.2.0
  - 0.2.1
  - 0.3.0
  - 0.4.0
  - 0.4.1
  - 0.4.2
  - 0.5.0
  - 0.5.1
  - 0.5.2
  - 0.6.0
  - 0.7.0
  - 0.8.0
  - 0.8.1
  - 0.8.2
  - 0.9.0
  - 0.9.0.1
  - 0.9.1
  - 1.0.0
  - 1.1.0
  - 1.1.1.dev0
  - 1.10.0
  - 1.11.0
  - 1.12.0
  - 1.12.1
  - "1.13"
  - 1.13.1
  - 1.14.0
  - 1.14.1
  - 1.15.0
  - 1.16.0
  - 1.17.0
  - 1.18.0
  - 1.19.0
  - 1.2.0
  - 1.20.0
  - 1.20.1
  - 1.20.2
  - 1.21.0
  - 1.22.0
  - 1.23.0
  - 1.23.1
  - 1.24.0
  - 1.25.0
  - 1.25.1
  - 1.26.0
  - 1.26.1
  - 1.27.0
  - 1.28.0
  - 1.29.0
  - 1.3.0
  - 1.30.0
  - 1.30.1
  - 1.4.0
  - 1.5.0
  - 1.6.0
  - 1.7.0
  - 1.7.1
  - 1.7.2
  - 1.8.0
  - 1.9.0
  - 1.9.1
  - 2.0.0
  - 2.0.0rc0
  - 2.0.1
  - 2.1.0
  - 2.1.1
  - 2.10.0
  - 2.10.1
  - 2.10.2
  - 2.11.0
  - 2.11.1
  - 2.11.2
  - 2.11.3
  - 2.11.4
  - 2.12.0
  - 2.12.1
  - 2.12.2
  - 2.13.0
  - 2.13.1
  - 2.13.2
  - 2.14.0
  - 2.14.0rc0
  - 2.14.1
  - 2.14.2
  - 2.14.2.dev0
  - 2.14.3
  - 2.15.0
  - 2.15.0rc0
  - 2.15.1
  - 2.16.0
  - 2.16.1
  - 2.16.2
  - 2.17.0
  - 2.17.0rc0
  - 2.17.1
  - 2.17.2
  - 2.18.0
  - 2.18.0rc0
  - 2.19.0
  - 2.19.0rc0
  - 2.2.0
  - 2.2.1
  - 2.2.2
  - 2.20.0
  - 2.20.0rc0
  - 2.20.1
  - 2.20.2
  - 2.20.3
  - 2.20.4
  - 2.21.0
  - 2.21.0rc0
  - 2.21.1
  - 2.21.2
  - 2.21.3
  - 2.22.0
  - 2.22.0rc0
  - 2.22.1
  - 2.22.2
  - 2.22.3
  - 2.22.4
  - 2.22.5
  - 2.3.0
  - 2.3.1
  - 2.3.2
  - 2.4.0
  - 2.4.1
  - 2.4.2
  - 2.5.0
  - 2.6.0
  - 2.7.0
  - 2.7.1
  - 2.8.0
  - 2.8.1
  - 2.9.0
  - 2.9.1
  - 2.9.2
  - 3.0.0
  - 3.0.0rc0
  - 3.0.0rc1
  - 3.0.0rc2
  - 3.0.0rc3
  - 3.0.1
  - 3.1.0
  - 3.1.0rc0
  - 3.1.1
  - 3.1.2
  - 3.1.3
  - 3.1.4
  - 3.10.0
  - 3.10.0rc0
  - 3.10.1
  - 3.11.0rc0
  - 3.11.0rc1
  - 3.2.0
  - 3.2.0rc0
  - 3.3.0
  - 3.3.0rc0
  - 3.3.1
  - 3.3.2
  - 3.4.0
  - 3.4.0rc0
  - 3.5.0
  - 3.5.0rc0
  - 3.5.1
  - 3.6.0
  - 3.6.0rc0
  - 3.7.0
  - 3.7.0rc0
  - 3.8.0
  - 3.8.0rc0
  - 3.8.1
  - 3.9.0
  - 3.9.0rc0
references:
- type: ADVISORY
  url: https://nvd.nist.gov/vuln/detail/CVE-2026-4137
- type: WEB
  url: https://github.com/mlflow/mlflow/commit/1dcbb0c2fbd1f446c328830e601ca13a28219b8a
- type: ADVISORY
  url: https://github.com/advisories/GHSA-4x5p-f36r-mxxr
- type: PACKAGE
  url: https://github.com/mlflow/mlflow
- type: WEB
  url: https://huntr.com/bounties/648dc30b-76c7-4433-86b8-f43d926fd8d6
- type: PACKAGE
  url: https://pypi.org/project/mlflow
- type: ADVISORY
  url: https://github.com/advisories/GHSA-f2m9-wcf4-cwwx
severity:
- type: CVSS_V3
  score: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H