MCP Shield

Name: MCP Shield
Author: sophiacave

by sophiacaveversion 1.0.7i★ –iRuns on your computer

Registry nameio.github.sophiacave/mcp-shield

Install

Overview

Description from the maker (original English)

Security scanner for MCP servers. SSRF, path traversal, injection, auth, secrets. Grade A-F.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Cybersecurity

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
The registry lists no key to fill in.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "shield": {
      "command": "npx",
      "args": [
        "-y",
        "@sophiacave/mcp-shield"
      ]
    }
  }
}

Run this in your terminal

claude mcp add shield -- npx -y @sophiacave/mcp-shield

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "shield": {
      "command": "npx",
      "args": [
        "-y",
        "@sophiacave/mcp-shield"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "shield": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@sophiacave/mcp-shield"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 8, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account sophiacave, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Cybersecurityi

More stars than 0% of the other 995 servers in this category
Published to the registry more recently than 20% of the other 995 servers in this category
Basic checks equal to or better than 100% of the other 995 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is MCP Shield safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (1.0.7) reached the registry 5 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: MCPProxy, ConnectSecure MCP, EchelonGraph CVE & Exposure

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

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EchelonGraph CVE & Exposure

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CVE, KEV, EPSS, SBOM and advisory lookups; per-CVE exposure from Shodan data (© Shodan). Keyless.

Computer or cloudUpdated today

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

MCP Shield

Open-source security scanner for MCP servers. 20 rules across 6 categories. Scan any server in seconds. Get a grade from A to F.

36.7% of MCP servers are SSRF-vulnerable (BlueRock, 2026). 82% have path traversal flaws. Only 17% are production-ready. MCP Shield finds the vulnerabilities before attackers do.

Quick Start

git clone https://github.com/sophiacave/mcp-shield

cd mcp-shield

Scan a file

python3 src/cli.py scan path/to/mcp_server.py

Scan a project

python3 src/cli.py scan path/to/mcp-project/

What It Checks (20 Rules)

Rule	Severity	What It Detects
SSRF-01	Critical	User input in HTTP request URLs
SSRF-02	Medium	Dynamic URLs without validation
SSRF-03	Medium	DNS rebinding (URL validated but no IP pinning)
PATH-01	High	User input in file paths
PATH-02	Medium	No path traversal protection
PATH-03	Medium	Symlink following without check
INJ-01	Critical	eval/exec on user input
INJ-02	Critical	SQL string interpolation
INJ-03	High	subprocess with shell=True
INJ-04	High	Template injection via .format()
INJ-05	Critical	Unsafe deserialization (pickle/yaml)
AUTH-01	Medium	No auth on tool handlers
AUTH-02	Critical	Hardcoded secrets/API keys (OpenAI, Stripe, GitHub, AWS)
AUTH-03	Low	No rate limiting on tool endpoints
SEC-01	High	SSL verification disabled
SEC-02	Medium	Wildcard CORS
SEC-03	Medium	Stack traces/error details exposed to client
SEC-04	Low	No input length validation (DoS risk)
LOG-01	Low	No logging/audit trail on tool invocations

Testing

python3 tests/test_integration.py

28 tests, 0 failures

MCP Server Integration

Add to ~/.claude/mcp.json:

"mcpServers": { "mcp-shield": { "command": "python3", "args": ["/path/to/mcp-shield/src/mcp_server.py"] } } }

Claude Code tools: shield_scan_file, shield_scan_directory, shield_scan_code

Example Output

MCP Shield: my-server/ — 3 finding(s)

[CRIT] SSRF-01: Potential SSRF: Dynamic URL from user input requests call with dynamic URL that may include user input Location: server.py:45 Fix: Validate URL against allowlist. Block internal IPs. CWE: CWE-918

[HIGH] INJ-03: Command injection: subprocess with shell=True subprocess called with shell=True. User input in args = RCE. Location: tools.py:112 Fix: Use subprocess with shell=False and pass args as list. CWE: CWE-78

[MED] AUTH-01: No authentication detected on tool handlers MCP tool handlers found but no auth logic detected Fix: Add authentication middleware. CWE: CWE-306

Grade: F | 1 critical, 1 high, 1 medium

Features

Zero dependencies — Pure Python, no pip installs required
20 security rules across SSRF, path traversal, injection, auth, config, and logging
CWE references — Every finding maps to a Common Weakness Enumeration ID
Actionable fixes — Each finding includes specific remediation steps
A-F grading — Instant security posture assessment
Dual mode — Run as CLI or as an MCP server inside Claude Code
Fast — Scans a typical MCP server in under 1 second

Why This Exists

The MCP ecosystem has 9,400+ servers and 97M monthly SDK downloads. Security tooling hasn't kept up. We built MCP Shield because every MCP server deployed without a security scan is a liability.

Built by Like One, a 501(c)(3) nonprofit. Security tooling should be free.

License

MIT — Like One

MCP Shield

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Cybersecurityi

Common questions

Alternatives

MCPProxy

ConnectSecure MCP

EchelonGraph CVE & Exposure

README from the maker

MCP Shield

Quick Start

Scan a file

Scan a project

What It Checks (20 Rules)

Testing

28 tests, 0 failures

MCP Server Integration

Example Output

Features

Why This Exists

License