MCP Servers

A collection of Model Context Protocol servers, templates, tools and more.

M
MCP Safeguard
by @Li-Bailiang
GitHub Repo(1 stars)

Security scanner and runtime protection for Model Context Protocol servers

Created 6/5/2026
Updated about 6 hours ago
README
View Source
Repository documentation and setup instructions

MCP-Safeguard

License: MIT CI Status Node.js TypeScript

A security scanner for Model Context Protocol (MCP) servers, built on Semgrep.

Protect your MCP servers with static analysis, runtime protection, and a curated set of MCP-focused security rules plus general-purpose SAST. MCP-Safeguard ships 170 security rules — 82 MCP/JS/Python/config rules (including dedicated MCP-threat rules for tool poisoning, rug-pulls, cross-server shadowing, and credential passthrough) plus 88 general-purpose Go/Java/Rust SAST rules.

Who is this for?

  • You're building an MCP server — run a pre-commit self-check to catch command injection, hardcoded secrets, prompt-injection sinks, and over-broad tool permissions before they ship.
  • Your team installs third-party MCP servers — audit an unfamiliar server for tool poisoning, rug-pulls, and credential passthrough before you connect it to an agent that can act on your behalf.
  • You run CI — wire the scan into a pull-request gate that fails on high-severity findings and uploads SARIF to GitHub's Security tab.

If any of those sound like you, the Quick Start below gets you a first scan in under a minute.

⚡ Quick Start

npm install -g @mcp-safeguard/cli
mcp-safeguard scan ./my-mcp-server

On its first run, MCP-Safeguard will download/install Semgrep if it isn't already available.

🎯 Feature Highlights

✨ MCP-Focused + General SAST - 170 rules: 82 MCP/JS/Python/config plus 88 general-purpose Go/Java/Rust SAST
🚀 Built on Semgrep - Downloads/installs Semgrep on first run if needed
🎨 Beautiful Output - Colored tables, clear actionable results
🔒 Runtime Protection - SDK for active security during execution
🤖 CI/CD Ready - GitHub Actions, GitLab, Jenkins, Azure DevOps
📊 Risk Scoring - Weighted 0-100 risk assessment
🌍 Multi-Language - JavaScript, TypeScript, Python, Go, Java, Rust
🐳 Docker Support - Build a container from source
📝 Multiple Formats - JSON, SARIF, Text, and HTML reports

📊 Example Scan Output

Real output from scanning a deliberately vulnerable MCP server (the vulnerable-extended fixture in this repo):

MCP-Safeguard scan output

Prefer plain text? Show the same scan output (findings truncated to the first few rows; the real scan reports all 18) 
┌────────────┬────────────────────┬──────────────────────────────┬────────┬──────────────────────────────────────────────────┐
│ Severity   │ Category           │ File                         │ Line   │ Message                                          │
├────────────┼────────────────────┼──────────────────────────────┼────────┼──────────────────────────────────────────────────┤
│ [!] ERROR  │ supply-chain       │ index.js                     │ 2      │ Suspicious use of child_process exec functions   │
│            │                    │                              │        │ without proper sanitization                      │
├────────────┼────────────────────┼──────────────────────────────┼────────┼──────────────────────────────────────────────────┤
│ [!] ERROR  │ supply-chain       │ index.js                     │ 13     │ Dangerous use of eval() function                 │
├────────────┼────────────────────┼──────────────────────────────┼────────┼──────────────────────────────────────────────────┤
│ [*]        │ supply-chain       │ index.js                     │ 17     │ Use of vm.runInNewContext with untrusted code    │
│ WARNING    │                    │                              │        │                                                  │
├────────────┼────────────────────┼──────────────────────────────┼────────┼──────────────────────────────────────────────────┤
│ [!] ERROR  │ shadow-server      │ index.js                     │ 28     │ Hardcoded credentials in MCP configuration       │
├────────────┼────────────────────┼──────────────────────────────┼────────┼──────────────────────────────────────────────────┤
│ [!] ERROR  │ excessive-agency   │ index.js                     │ 34     │ Automatic file deletion without confirmation     │
└────────────┴────────────────────┴──────────────────────────────┴────────┴──────────────────────────────────────────────────┘

  ... plus 13 more findings in server.py and index.js (SSL verification
  disabled, environment-variable exposure, shell=True subprocess, SSRF, … )

=== Scan Summary ===

┌───────────────────────────┬───────┐
│ Total Findings            │ 18    │
├───────────────────────────┼───────┤
│ High Severity (ERROR)     │ 13    │
├───────────────────────────┼───────┤
│ Medium Severity (WARNING) │ 5     │
├───────────────────────────┼───────┤
│ Low Severity (INFO)       │ 0     │
├───────────────────────────┼───────┤
│ Risk Score                │ 62.00 │
└───────────────────────────┴───────┘

Top Categories:
  - supply-chain: 5
  - shadow-server: 5
  - excessive-agency: 3
  - indirect-injection: 2
  - dos: 2

Scan completed in 29056ms

Exit code is 1 when any finding meets the fail-on threshold (default: high/ERROR), so the scan doubles as a CI gate. A clean scan prints ✓ No security issues found! and exits 0.

🚀 Installation

npm

npm install -g @mcp-safeguard/cli
mcp-safeguard scan .

From Source (requires pnpm)

git clone https://github.com/Li-Bailiang/mcp-safeguard
cd mcp-safeguard
pnpm install
pnpm build
node packages/cli/dist/index.js scan .

Docker

Build the image from source:

docker build -t mcp-safeguard .
docker run -v $(pwd):/workspace mcp-safeguard scan /workspace

Prerequisites: Semgrep — MCP-Safeguard downloads/installs it on first run if it is not already present.

📖 Usage

Basic Scanning

# Scan current directory (downloads/installs Semgrep on first run if needed)
mcp-safeguard scan .

# Scan specific directory
mcp-safeguard scan ./packages/server

# Filter by severity
mcp-safeguard scan . --severity error

Output Formats

# JSON for programmatic use
mcp-safeguard scan . --format json -o report.json

# SARIF for CI/CD integration
mcp-safeguard scan . --format sarif -o results.sarif

# Text with colors (default)
mcp-safeguard scan . --format text

Ignore Files

Create .mcpignore in your project root:

# gitignore-style patterns
node_modules/
dist/
build/
*.test.ts
test-fixtures/
**/__mocks__/

🛡️ Security Categories

MCP-Safeguard ships 170 security rules in total: 82 MCP/JS/Python/config rules plus 88 general-purpose Go/Java/Rust SAST rules. The MCP-focused rules are organized into 8 categories (the Go/Java/Rust SAST packs are documented in the rules reference):

1. MCP Threats (6 rules)

Detect attacks specific to the Model Context Protocol — these inspect the modern McpServer.tool() / registerTool() API, not just variable names

  • ❌ Tool poisoning — hidden instructions in a tool description
  • ❌ Rug-pull — tool description computed at runtime (can change after approval)
  • ❌ Cross-server shadowing — a description that overrides another server's tools
  • ❌ Credential passthrough — forwarding a server secret into an outbound request

2. Supply Chain (6 rules)

Detect malicious package usage and injection risks

  • ❌ Command injection via exec(), eval()
  • ❌ Dynamic imports with user input
  • ❌ Unsafe subprocess calls (Python)

3. Shadow Server (11 rules)

Catch insecure MCP server configurations

  • ❌ Missing authentication checks
  • ❌ Hardcoded credentials in code
  • ❌ Disabled TLS verification
  • ❌ Unrestricted CORS policies
  • ❌ Debug mode in production

4. Indirect Injection (8 rules)

Find external content handling vulnerabilities

  • ❌ SSRF (Server-Side Request Forgery)
  • ❌ Path traversal attacks
  • ❌ Prompt injection risks
  • ❌ SQL injection vulnerabilities
  • ❌ XML external entity attacks

5. Excessive Agency (8 rules)

Identify autonomous actions without validation

  • ❌ Destructive operations without user confirmation
  • ❌ Automatic code execution
  • ❌ Unrestricted file writes
  • ❌ Unrestricted network access

6. Context Overshare (7 rules)

Prevent excessive data exposure

  • ❌ Environment variable leaks
  • ❌ Credentials in logs or prompts
  • ❌ Excessive file system access
  • ❌ PII (Personally Identifiable Information) exposure

7. Typosquatting (4 rules)

Detect package name confusion attacks

  • ❌ Package names similar to popular MCP packages
  • ❌ Homoglyph characters in names
  • ❌ Namespace confusion attacks

8. DoS (Denial of Service) (7 rules)

Prevent resource exhaustion vulnerabilities

  • ❌ Unbounded loops without limits
  • ❌ Uncontrolled recursion
  • ❌ Large file processing without size checks
  • ❌ ReDoS (Regular Expression DoS)
  • ❌ Uncontrolled memory allocation

📘 Complete Rule Documentation

🔌 Runtime Protection SDK

Add active security to your running MCP server:

import { MCPSafeguardRuntime } from '@mcp-safeguard/runtime';
import { Server } from '@modelcontextprotocol/sdk/server/index.js';

// Initialize runtime protection
const shield = new MCPSafeguardRuntime({
  blockDangerousTools: true,           // Block dangerous operations
  maxToolCallsPerMinute: 60,           // Rate limiting
  promptInjectionDetection: true,      // Detect prompt injection
  auditLogPath: './logs/audit.log',    // Security event logging
  circuitBreakerThreshold: 5           // Failure threshold
});

shield.init();

// Create MCP server
const server = new Server({
  name: 'protected-server',
  version: '1.0.0'
});

// Wrap tool functions with security checks
server.setRequestHandler('tools/call', async (request) => {
  const { name, arguments: args } = request.params;
  
  // Wrap with protection
  const safeTool = shield.wrapToolCall(name, async (args) => {
    // Your tool implementation
    return executeToolLogic(name, args);
  });
  
  try {
    const result = await safeTool(args);
    return { content: [{ type: 'text', text: JSON.stringify(result) }] };
  } catch (error) {
    // Tool blocked by MCP-Safeguard
    throw new Error(`Security check failed: ${error.message}`);
  }
});

// Validate prompts before sending to LLM
server.setRequestHandler('prompts/get', async (request) => {
  const promptText = generatePrompt(request.params);
  
  const validation = shield.validatePrompt(promptText);
  if (!validation.allowed) {
    throw new Error(`Prompt injection detected: ${validation.reason}`);
  }
  
  return { messages: [{ role: 'user', content: { type: 'text', text: promptText } }] };
});

// Graceful shutdown with audit log flushing
process.on('SIGINT', async () => {
  await shield.shutdown();
  process.exit(0);
});

Runtime SDK Features:

  • ✅ Tool call interception and validation
  • ✅ Rate limiting (prevent DoS)
  • ✅ Prompt injection detection
  • ✅ Audit logging (complete event trail)
  • ✅ Circuit breaker (prevent cascading failures)
  • ✅ Custom validation hooks
  • ✅ Real-time metrics

📘 Runtime SDK Documentation

🤖 CI/CD Integration

Install the published CLI in CI with npm install -g @mcp-safeguard/cli, then run mcp-safeguard scan ....

GitHub Actions

Use the composite action shipped in this repo — it builds the CLI from source, runs the scan, uploads SARIF to GitHub Security, and fails the job on the chosen severity:

name: MCP Security Scan

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main, develop]

permissions:
  contents: read
  security-events: write

jobs:
  security-scan:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: Li-Bailiang/mcp-safeguard@main
        with:
          fail-on-severity: high   # high | medium | low
          working-directory: '.'

GitLab CI

mcp-security-scan:
  stage: security
  image: node:20
  before_script:
    - npm install -g @mcp-safeguard/cli
  script:
    - mcp-safeguard scan . --format sarif -o results.sarif
  artifacts:
    reports:
      sast: results.sarif
    paths:
      - results.sarif
    expire_in: 30 days

Jenkins

pipeline {
    agent any
    stages {
        stage('Security Scan') {
            steps {
                sh 'npm install -g @mcp-safeguard/cli'
                sh 'mcp-safeguard scan . -f sarif -o results.sarif'
            }
        }
    }
    post {
        always {
            recordIssues(tools: [sarif(pattern: 'results.sarif')])
        }
    }
}

Azure DevOps

- task: NodeTool@0
  inputs:
    versionSpec: '18.x'

- script: |
    npm install -g @mcp-safeguard/cli
    mcp-safeguard scan $(Build.SourcesDirectory) -f sarif -o results.sarif
  displayName: 'MCP Security Scan'

- task: PublishSecurityAnalysisLogs@3
  inputs:
    ArtifactName: 'CodeAnalysisLogs'

📘 Complete CI/CD Integration Guide

📊 Real-World Example

Before MCP-Safeguard

// ❌ Multiple security vulnerabilities
import { exec } from 'child_process';

server.setRequestHandler('tools/call', async (request) => {
  const { name, arguments: args } = request.params;
  
  // No authentication
  // No input validation
  // Command injection vulnerability
  exec(`ls ${args.path}`, (error, stdout) => {
    return stdout;
  });
});

MCP-Safeguard Detection:

  • 🔴 ERROR: Missing authentication check
  • 🔴 ERROR: Command injection via exec()
  • 🔴 ERROR: Unvalidated user input in shell command

After MCP-Safeguard

// ✅ Secure implementation
import { execFile } from 'child_process';
import { validatePath, isAuthenticated } from './security';

server.setRequestHandler('tools/call', async (request) => {
  const { name, arguments: args } = request.params;
  
  // Authentication check
  if (!isAuthenticated(request)) {
    throw new Error('Unauthorized: Authentication required');
  }
  
  // Input validation
  const safePath = validatePath(args.path);
  if (!safePath) {
    throw new Error('Invalid path: Path traversal detected');
  }
  
  // Safe execution with argument array (not shell)
  return new Promise((resolve, reject) => {
    execFile('ls', ['-la', safePath], (error, stdout) => {
      if (error) reject(error);
      else resolve(stdout);
    });
  });
});

MCP-Safeguard Result:

  • ✅ All security checks passed
  • ✅ Risk score: 0/100 (LOW)

🌟 Language Support

| Language | Coverage | Rules | |----------|----------|-------| | JavaScript / TypeScript | MCP-specific threat packs + general patterns | exec()/eval(), CORS, auth, injection, agency, DoS | | Python | MCP-specific threat packs (mcp-python-*) + general patterns | subprocess, eval(), SSRF, env exposure | | Go | General-purpose SAST | 27 (concurrency, injection, TLS, crypto) | | Java | General-purpose SAST | 32 (SQLi, XXE, deserialization, LDAP) | | Rust | General-purpose SAST | 29 (unsafe, crypto, error handling) | | Infrastructure | Config / IaC | 25 (Dockerfile, Kubernetes, MCP config) |

The Go/Java/Rust packs are general-purpose static-analysis rules, not MCP-specific. They run only when files of that language are present in the scan target.

💡 Why MCP-Safeguard?

vs Other Security Tools

| Feature | MCP-Safeguard | Snyk | SonarQube | Semgrep OSS | LLM Guard | |---------|------------|------|-----------|-------------|-----------| | MCP-Specific Rules | ✅ 57 | ❌ | ❌ | ❌ | ⚠️ | | Runtime Protection | ✅ | ❌ | ❌ | ❌ | ✅ | | Static Analysis | ✅ | ✅ | ✅ | ✅ | ❌ | | Zero Config | ✅ | ⚠️ | ⚠️ | ✅ | ⚠️ | | Price | Free | Paid | Community/Paid | Free | Free | | Offline Mode | ✅ | ❌ | ⚠️ | ✅ | ✅ | | CI/CD Integration | ✅ | ✅ | ✅ | ✅ | ⚠️ |

📘 Detailed Comparison

MCP-Safeguard is the only tool purpose-built for MCP servers.

📚 Documentation

📖 Getting Started Guide - First scan in 5 minutes
🏗️ Architecture Overview - System design and components
🔧 Rule Development - Create custom security rules
📋 API Reference - Programmatic usage
🤖 CI/CD Integration - Automate security scans
❓ FAQ - Common questions and troubleshooting
⚖️ Comparison - vs Snyk, SonarQube, Semgrep, LLM Guard

🤖 Claude Code Skill

This repository includes a Claude Code project skill at .claude/skills/mcp-safeguard/ to help AI assistants run MCP-Safeguard, explain findings, suggest minimal fixes, and add GitHub Actions scanning. Open the repo in Claude Code and ask it to scan an MCP server or wire MCP-Safeguard into CI.

The skill drives the published @mcp-safeguard/cli package; it does not reimplement scanning logic and never needs passwords, OTP codes, recovery codes, or API secrets.

🐳 Docker Support

# Build image
docker build -t mcp-safeguard .

# Scan a directory
docker run -v $(pwd):/workspace mcp-safeguard scan /workspace

# Export results
docker run -v $(pwd):/workspace \
  mcp-safeguard scan /workspace -f json -o /workspace/report.json

No pre-built image is published yet — build it locally with docker build -t mcp-safeguard ..

🔧 Development

# Clone repository
git clone https://github.com/Li-Bailiang/mcp-safeguard.git
cd mcp-safeguard

# Install dependencies (requires pnpm)
pnpm install

# Build all packages
pnpm build

# Run tests
pnpm test

# Lint code
pnpm lint

# Clean build artifacts
pnpm clean

Monorepo Structure:

mcp-safeguard/
├── packages/
│   ├── cli/                # Command-line interface
│   ├── core/               # Scanning engine + rules
│   ├── runtime/            # Runtime protection SDK
│   └── semgrep-installer/  # Auto-installer
├── tests/                  # Test fixtures
└── docs/                   # Documentation

🤝 Contributing

We welcome contributions! Help make MCP security better for everyone.

Ways to Contribute

Quick Contribution Guide

  1. Fork the repository
  2. Create a feature branch: git checkout -b feature/my-rule
  3. Make your changes
  4. Add tests
  5. Submit a pull request

📘 Contributing Guidelines

💬 Community & Support

🗺️ Roadmap

Already shipped in 0.1.0

  • ✅ HTML report generation with charts
  • ✅ Auto-fix suggestions (--fix / --dry-run)
  • ✅ Go, Rust, and Java SAST packs
  • ✅ GitHub composite action + SARIF upload

Next

  • [x] Publish to npm
  • [ ] Baseline / diff comparison (track improvements over time)
  • [ ] VS Code extension for real-time scanning
  • [ ] Web dashboard for results visualization
  • [ ] Rule marketplace for community rules

Later

  • [ ] Plugin system for extensibility
  • [ ] Deeper taint analysis for MCP data flows
  • [ ] Enterprise features (SSO, RBAC)

🔒 Security

Found a security vulnerability in MCP-Safeguard?

Please report it responsibly: SECURITY.md

We take security seriously and will respond within 48 hours.

📄 License

MIT License - see LICENSE for details.

TL;DR: Free for commercial and personal use.

🙏 Acknowledgments

  • Semgrep - Powerful static analysis engine
  • MCP Community - Feedback and testing
  • Contributors - Everyone who helped improve MCP-Safeguard
  • Security Researchers - Responsible disclosure and improvements

📞 Get in Touch

Built with ❤️ for the MCP community

⭐ Star on GitHub • 📖 Documentation • 🐛 Report Issue • 💬 Discuss

Secure your MCP servers today.

git clone https://github.com/Li-Bailiang/mcp-safeguard && cd mcp-safeguard && pnpm install && pnpm build
node packages/cli/dist/index.js scan /path/to/your-mcp-server
Quick Setup
Installation guide for this server

Install Package (if required)

npx @modelcontextprotocol/server-mcp-safeguard

Cursor configuration (mcp.json)

{ "mcpServers": { "li-bailiang-mcp-safeguard": { "command": "npx", "args": [ "li-bailiang-mcp-safeguard" ] } } }
Author Servers
Other servers by Li-Bailiang

MCP Safeguard Skill

Claude Code skill for MCP-Safeguard security scanning

1