Insecure File Permissions in MLflow Affecting Directory Management

CVE-2026-4137

What is CVE-2026-4137?

In certain versions of MLflow prior to 3.11.0, specific functions for managing temporary directories inadvertently set insecure permissions, making these directories world-writable (0o777) and group-writable (0o770). This oversight allows local attackers to modify model artifacts, potentially leading to arbitrary code execution during deserialization processes with cloudpickle.load(). The vulnerability poses a significant risk, especially in shared environments like Databricks, where NFS mounts are commonly used. This issue is an extension of previously identified vulnerabilities, emphasizing the need for stringent security practices in directory and file management.

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