PYSEC-2026-2628 MCP Run Python has a Sandbox Escape & Server Takeover Vulnerability

Impact Critical Sandbox Escape & Server Takeover: A critical security vulnerability exists in mcp-run-python due to a lack of isolation between the Python runtime Pyodide and the host JavaScript environment. The runPython and runPythonAsync functions execute Python code using Pyodide without...

MCP Run Python has a Sandbox Escape & Server Takeover Vulnerability

Impact Critical Sandbox Escape & Server Takeover: A critical security vulnerability exists in mcp-run-python due to a lack of isolation between the Python runtime Pyodide and the host JavaScript environment. The runPython and runPythonAsync functions execute Python code using Pyodide without...

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 environment. This may result in an attacker hijacking the MCP server - for malicious purposes including MCP tool shadowing...