The MCP docs now say it plainly. The protocol can not vouch for a local server.
By Lior AharonovFounder, 7IT Solutions ·
On Monday, 5 October 2026, the MCP project merged a security guide for servers that run on your own machine. It names five threats (malicious servers, overcollecting servers, compromised dependencies, poisoned tool catalogs and vulnerable components) and calls running third-party servers in containers the most effective control.
A local server runs with your rights. Without isolation, the package you added for a weather lookup can read the same SSH keys you can.
Pin every local server to an exact version, give each one its own narrow token, and run third-party ones in a container that mounts only the project folder.
Every npx line in your config is a stranger you let in with your keys. Treat it like one.
Lior Aharonov · my takeSources
- MCP pull request 3072: local server security guide github.com
- MCP docs: Local server security github.com
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