← Vulnerability feed

Vulnerability record · CVE-2026-4137 · published 18 May 2026

CVE-2026-4137: Lfprojects mlflow vulnerability

Lfprojects · Mlflow

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.

7.8 CVSS 3.1 High EPSS 0.16% · top 95.3% CWE-378 · CWE-378
7.8CVSS 3.1 base score
0.16%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References, 2 tagged exploit
24 Jul 2026Last modified by NVD

Description

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.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/mlflow/mlflow/commit/1dcbb0c2fbd1f446c328830e601ca13a28219b8a Patch
https://huntr.com/bounties/648dc30b-76c7-4433-86b8-f43d926fd8d6 ExploitThird Party Advisory
https://huntr.com/bounties/648dc30b-76c7-4433-86b8-f43d926fd8d6 ExploitThird Party Advisory

Track CVE-2026-4137 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.3CVE-2026-64849MLflow unauthenticated webhook test endpoint SSRF via redirectMLflow before 3.15.0 validates the webhook URL only on the original request, while the delivery code follows redirects and re-resolves the hostname w…KEVEPSS 9.8%analysed10.0CVE-2025-15379Lfprojects mlflow command injection vulnerabilityA command injection vulnerability exists in MLflow's model serving container initialization code, specifically in the `_install_model_dependencies_to…EPSS 2.4%10.0CVE-2025-15036Lfprojects mlflow path traversal vulnerabilityA path traversal vulnerability exists in the `extract_archive_to_dir` function within the `mlflow/pyfunc/dbconnect_artifact_cache.py` file of the mlf…EPSS 0.58%10.0CVE-2023-3765MLflow absolute path traversal before 2.5.0MLflow versions prior to 2.5.0 contain an absolute path traversal flaw (CWE-36) in the GitHub repository mlflow/mlflow. The vulnerability allows an u…EPSS 68%analysed9.8CVE-2026-0545Lfprojects mlflow missing authentication for critical function vulnerabilityIn mlflow/mlflow, the FastAPI job endpoints under `/ajax-api/3.0/jobs/*` are not protected by authentication or authorization when the `basic-auth` a…EPSS 4.4%9.8CVE-2025-11200Lfprojects mlflow weak password requirements vulnerabilityMLflow Weak Password Requirements Authentication Bypass Vulnerability. This vulnerability allows remote attackers to bypass authentication on affecte…EPSS 1.5%9.8CVE-2025-11201Lfprojects mlflow path traversal vulnerabilityMLflow Tracking Server Model Creation Directory Traversal Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute …EPSS 27%9.8CVE-2023-6974Lfprojects mlflow server-side request forgery (ssrf) vulnerabilityA malicious user could use this issue to access internal HTTP(s) servers and in the worst case (ie: aws instance) it could be abuse to get a remote c…EPSS 1.5%

Source: NIST National Vulnerability Database (record CVE-2026-4137), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.