MCP Security Kit by Agent Trust Cloud

medium

MCP server container shares the host network

The container runs with --network host.

Why it matters

The server can reach every service listening on your machine, including ones bound to localhost that assume only you can reach them.

How to fix it

Use the default bridge network and publish only the ports that are needed.

Before

{
  "mcpServers": {
    "tools": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "--network",
        "host",
        "acme/mcp-tools:1.4.0"
      ]
    }
  }
}

After

{
  "mcpServers": {
    "tools": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "acme/mcp-tools:1.4.0"
      ]
    }
  }
}

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

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