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OpenAdvisories
Medium · 5.8 CVE-2026-25905 EUVD-2026-6610GHSA-pfv4-wmph-5gc6PYSEC-2026-2628

Lack of isolation in mcp-run-python leads to MCP server takeover

Published Feb 9, 2026 · Updated Feb 9, 2026 · Assigned by JFROG

Description

The Python code being run by 'runPython' or 'runPythonAsync' is not isolated from the rest of the JS code, allowing any Python code to use the Pyodide APIs to modify the JS environment. This may result in an attacker hijacking the MCP server - for malicious purposes including MCP tool shadowing. Note - the "mcp-run-python" project is archived and unlikely to receive a fix.

Affected products

VendorProductAffectedFixed
— mcp-run-python — —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI mcp-run-python <= 0.0.22 — GHSA-pfv4-wmph-5gc6

References