CVSS 3.1
5.8 mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:LCVE-2026-25905
Medium (5.8). EPSS 0.2% chance of exploitation in the next 30 days.
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.
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 10% of CVEs (scores of 2026-10-31)
- CWE
- CWE-653
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-pfv4-wmph-5gc6 | PyPI | mcp-run-python | <=0.0.22 | no fix published |
| PYSEC-2026-2628 | PyPI | mcp-run-python | <=0.0.22 | no fix published |