In mysql-mcp-server SSE/HTTP mode (MCP_TRANSPORT=sse), SseServerTransport is created without security_settings, disabling DNS-rebinding Origin/Host validation; the Starlette app lacks CORS/TrustedHost middleware and exposes unauthenticated /, /sse, /messages/ while binding 0.0.0.0. Remote attackers can call execute_sql → arbitrary SQL, data theft/modification, and with MySQL FILE privilege LOAD_FILE/INTO OUTFILE may enable RCE. Affects `