MCP Python SDK Flaw Exposes OAuth Credentials to Rogue Servers
Researchers have uncovered a serious weakness in the official Model Context Protocol (MCP) Python SDK that could enable a hostile server to harvest the OAuth tokens an application uses to authenticate with external services. The issue, which impacts several earlier releases, sees sensitive data such as client secrets, authorization codes, and PKCE proof keys being sent to an attacker‑controlled endpoint. The maintainers have released version 1.30.0 to address the problem, urging developers to upgrade promptly and review their authentication flows.
By Gourav Rajput

















