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.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-pfv4-wmph-5gc6 MCP Run Python has a Sandbox Escape & Server Takeover Vulnerability
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Tue, 10 Feb 2026 16:30:00 +0000

Type Values Removed Values Added
First Time appeared Mcp-run-python
Mcp-run-python mcp-run-python
Vendors & Products Mcp-run-python
Mcp-run-python mcp-run-python

Mon, 09 Feb 2026 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 09 Feb 2026 09:15:00 +0000

Type Values Removed Values Added
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.
Title Lack of isolation in mcp-run-python leads to MCP server takeover
Weaknesses CWE-653
References
Metrics cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: JFROG

Published:

Updated: 2026-02-09T12:55:24.415Z

Reserved: 2026-02-08T11:19:42.865Z

Link: CVE-2026-25905

cve-icon Vulnrichment

Updated: 2026-02-09T12:55:19.471Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-02-09T09:16:34.030

Modified: 2026-02-09T16:08:35.290

Link: CVE-2026-25905

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-02-10T16:26:56Z

Weaknesses