The Pydantic-AI MCP Run Python tool configures the Deno sandbox with an overly permissive configuration that allows the underlying Python code to access the localhost interface of the host to perform SSRF attacks. Note - the mcp-run-python project is archived and unlikely to receive a fix.
Weakness
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.