CVE-2026-25905
MEDIUMmcp-run-python - Improper Isolation via Pyodide API Access
Title source: llmDescription
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.
References (1)
Core 1
Core References
Various Sources third-party-advisory
https://research.jfrog.com/vulnerabilities/mcp-run-python-lack-of-isolation-mcp-takeover-jfsa-2026-001653030/
Scores
CVSS v3
5.8
EPSS
0.0001
EPSS Percentile
2.4%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:L
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
partial
Details
CWE
CWE-653
Status
published
Products (1)
pypi/mcp-run-python
0PyPI
Published
Feb 09, 2026
Tracked Since
Feb 18, 2026