CVE-2025-50460:
Python vulnerability analysis and mitigation

Overview

A remote code execution (RCE) vulnerability exists in the ms-swift project version 3.3.0, identified as CVE-2025-50460. The vulnerability was discovered in tests/run.py due to unsafe deserialization using yaml.load() from PyYAML library version 5.3.1. The issue was disclosed on August 1, 2025, and has been assigned a CVSS v3.1 base score of 9.8 (CRITICAL) (NVD).

Technical details

The vulnerability stems from the unsafe use of yaml.load() function in tests/run.py when processing YAML configuration files passed to the --run_config parameter. When a malicious YAML file is loaded, it allows for arbitrary Python command execution through deserialization, such as os.system() commands. The vulnerability is classified under CWE-502 (Deserialization of Untrusted Data) and has received a CRITICAL severity rating with a CVSS v3.1 score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) (NVD, GitHub Advisory).

Impact

If exploited, this vulnerability can lead to full system compromise through arbitrary code execution during the deserialization process. An attacker who can control the content of the YAML configuration file can execute arbitrary Python commands with the same privileges as the application process (GitHub POC).

Mitigation and workarounds

To mitigate this vulnerability, it is recommended to upgrade PyYAML to version 5.4 or higher and replace the usage of yaml.load() with yaml.safe_load(). This change prevents arbitrary code execution during YAML deserialization (NVD).