Medium severity5.8NVD Advisory· Published Feb 9, 2026· Updated Apr 15, 2026
CVE-2026-25905
CVE-2026-25905
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 packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
mcp-run-pythonPyPI | <= 0.0.22 | — |
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
4- github.com/advisories/GHSA-pfv4-wmph-5gc6ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-25905ghsaADVISORY
- research.jfrog.com/vulnerabilities/mcp-run-python-lack-of-isolation-mcp-takeover-jfsa-2026-001653030ghsaWEB
- research.jfrog.com/vulnerabilities/mcp-run-python-lack-of-isolation-mcp-takeover-jfsa-2026-001653030/nvd
News mentions
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