GPR-005 · high risk

Review new MCP servers

Require review when a supported harness attempts to use an MCP server that has not been reviewed.

Decision

review

Matcher

mcp = unreviewed-mcp-server

Reviewed

2026-08-09

Safe test cases

matching synthetic case

mcp = unreviewed-mcp-serverreview

different benign synthetic case

mcp = benign-unreviewed-mcp-serverunmatched

Limitations

  • MCP discovery and enforcement vary by harness and event surface.

Review before applying

This recipe is a starting point, not a universal security policy. Open it in Policy Studio, replace example identifiers where necessary, review scope and blast radius, simulate where supported, and use the normal approval flow before enforcement.

Recipe SHA-256: 3b821d75ad5837805ce9102f71f637c42fd281cb98f816c1dff8cc3f198931d7

When a policy is saved and delivered through Guard Cloud, it uses the existing Guard policy-bundle compiler. If the policy-bundle signing key is configured, that compiler produces an RSA-PSS-SHA256 signed bundle that local Guard verifies before applying.