PYSEC-2026-1617 Model Context Protocol (MCP) Python SDK does not enable DNS rebinding protection by default

Description The Model Context Protocol MCP Python SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without authentication using FastMCP with streamable HTTP or SSE transport, and has not configured...

GHSA-9H52-P55H-VW2F Model Context Protocol (MCP) Python SDK does not enable DNS rebinding protection by default

Description The Model Context Protocol MCP Python SDK does not enable DNS rebinding protection by default for HTTP-based servers. When an HTTP-based MCP server is run on localhost without authentication using FastMCP with streamable HTTP or SSE transport, and has not configured...