CVE-2026-25905 — Lack of isolation in mcp-run-python leads to MCP server takeover
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 envi…
Published: 2026-02-09 · CVSS: 5.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7