The MCP Python SDK, called mcp on PyPI, is a Python implementation of the Model Context Protocol (MCP). Prior to 1.28.1, the deprecated mcp.server.websocket.websocket_server transport accepted WebSocket handshakes without applying Host or Origin header validation, leaving no SDK-level way to restrict which origins could connect to applications that exposed that transport. This issue is fixed in version 1.28.1.
Weakness
The product does not properly verify that the source of data or communication is valid.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Mcp_python_sdk | Lfprojects | * | 1.28.1 (excluding) |
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/111.html
- https://cwe.mitre.org/data/definitions/141.html
- https://cwe.mitre.org/data/definitions/142.html
- https://cwe.mitre.org/data/definitions/160.html
- https://cwe.mitre.org/data/definitions/21.html
- https://cwe.mitre.org/data/definitions/384.html
- https://cwe.mitre.org/data/definitions/385.html
- https://cwe.mitre.org/data/definitions/386.html
- https://cwe.mitre.org/data/definitions/387.html
- https://cwe.mitre.org/data/definitions/388.html
- https://cwe.mitre.org/data/definitions/510.html
- https://cwe.mitre.org/data/definitions/59.html
- https://cwe.mitre.org/data/definitions/60.html
- https://cwe.mitre.org/data/definitions/75.html
- https://cwe.mitre.org/data/definitions/76.html
- https://cwe.mitre.org/data/definitions/89.html
References
- https://github.com/modelcontextprotocol/python-sdk/commit/777b8d06710c140e3606b0d4598e2aa48546c266
- https://github.com/modelcontextprotocol/python-sdk/pull/2992
- https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.28.1
- https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-vj7q-gjh5-988w