CVE-2026-25905
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.
Published:Feb 9, 2026
Last Modified:Apr 17, 2026
EPS:Feb 9, 2026
EPSS Score:0.00012
CVSS Score:5.8
Affected Products
Vendor
Product
Action
Vendor
Mcp-run-python
Product
Mcp-run-python
Mcp-run-python
Mcp-run-python
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
No CAPEC recorded yet
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
