GHSA-84M7-P3X7-PCFV MCP Python SDK: Unbounded Session Accumulation in StreamableHTTP Transport Enables Resource Exhaustion

Summary In affected versions, a Streamable HTTP server in stateful mode the default never reclaimed session state: - sessions did not expire; - a client DELETE ended the session but left its entry registered; - a session whose first request was refused stayed registered with a running task. Each...