MCP Security Kit by Agent Trust Cloud

medium

Unpinned MCP server package or image

The server is launched with npx, uvx, pipx or docker without an exact version, so each start fetches the newest release.

Why it matters

If the package or its publisher account is compromised, the new code runs with the server's access the next time your client starts. You also can't tell which version you ran yesterday.

How to fix it

Pin an exact version ([email protected] for npm, name==1.2.3 for Python, image@sha256:... for Docker) and update deliberately after reading the changes.

Before

{
  "mcpServers": {
    "fetch": {
      "command": "uvx",
      "args": [
        "mcp-server-fetch"
      ]
    }
  }
}

After

{
  "mcpServers": {
    "fetch": {
      "command": "uvx",
      "args": [
        "mcp-server-fetch==2025.4.7"
      ]
    }
  }
}

Illustrative configs. The checker flags the “before” version with this finding and not the “after” version.

Check your own config

Other checks