MCP Security Guard

MCP Security Guard

Find out if the MCP servers you installed are lying to your AI.

Local audit for tool poisoning, rug pulls, tool shadowing, hidden Unicode and leaked secrets, mapped to the OWASP MCP Top 10. Nothing leaves your machine unless you opt in.

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🚀 Quick Install

Cursor

Click the button above, or use this deep link: cursor://anysphere.cursor-deeplink/mcp/install?name=mcp-security-guard&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIm1jcC1zZWN1cml0eS1ndWFyZCJdfQ==

Or manually add to .cursor/mcp.json:

{

"mcpServers": { "mcp-security-guard": { "command": "npx", "args": ["-y", "mcp-security-guard"] } } }

Claude Code

Via Plugin (recommended)

/plugin marketplace add petrovicistefan/mcp-security-guard

/plugin install mcp-security-guard@mcp-security-guard

Then run /mcp-audit or ask Claude *"are my MCP servers safe?"*

Via CLI

claude mcp add mcp-security-guard -- npx -y mcp-security-guard

Claude Desktop

Add to your Claude Desktop config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS, %APPDATA%\Claude\claude_desktop_config.json on Windows):

{

"mcpServers": { "mcp-security-guard": { "command": "npx", "args": ["-y", "mcp-security-guard"] } } }

VS Code

Click the button above, or manually add to .vscode/mcp.json:

{

"mcpServers": { "mcp-security-guard": { "command": "npx", "args": ["-y", "mcp-security-guard"] } } }

Command Line

npx -y mcp-security-guard audit --project-only

⭐ Star this repository to support the project and stay updated! → Give a star

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📋 Table of Contents

• Why MCP Security Guard?
• Use Cases
• What It Checks
• OWASP MCP Top 10 Coverage
• Quick Demo (1 Minute)
• Tools
• CI / GitHub Action
• Interactive Dashboard
• Runtime Hooks
• Team Plan
• Benchmark Results
• Development
• Contributing
• Security & Privacy
• About the Author

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Why MCP Security Guard?

Your code is covered by other tools. This one checks the MCP servers that inject text into your AI's context.

MCP Security Guard audits every MCP server Claude (and other AI clients) can reach: servers you configured, servers that plugins bring, and servers from Claude Desktop and other clients on your machine.

How It Compares

*As of October 2026. Corrections welcome.*

Our differentiators:

• Native Claude Code integration with a /mcp-audit slash command and runtime protection
• Comprehensive rug-pull protection: pins and verifies tool definitions, skills, commands, subagents, and CLAUDE.md files
• Every finding mapped to OWASP MCP Top 10 for compliance and remediation guidance
• GitHub Action with SARIF for code scanning alerts on pull requests
• Agent Bill of Materials (BOM) in CycloneDX 1.6 format for audits and compliance
• Privacy-first: everything runs locally by default; network access is explicit opt-in

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Use Cases

1. Individual Developers

Protect your local AI setup.

• Audit MCP servers before and after installation
• Get warned if a server's tool definitions change (rug pulls)
• Runtime protection: block credentials from being sent, detect poisoned outputs
• Pin trusted servers and skills for continuous verification

# Scan before installing a new server

npx mcp-security-guard scan server-config.json --confirm-launch

Pin your reviewed servers

npx mcp-security-guard pin

Check everything is still safe

npx mcp-security-guard audit

2. Pull Request CI Checks

Block risky MCP servers and poisoned skills in code review.

Fail PRs that add:

• MCP servers with tool poisoning, unpinned packages, or privileged Docker images
• Skills or CLAUDE.md files with instruction overrides or credential exfiltration
• Vulnerable dependencies or typosquatted packages

Findings appear in GitHub's code scanning interface with OWASP MCP Top 10 references.

- uses: petrovicistefan/mcp-security-guard@main

with: fail-on: high

3. Teams and Enterprises

Central security policy for your organization.

With the Team plan:

• Admins publish one policy (allowed/blocked servers, plugins, pinned versions)
• Everyone's plugin enforces it automatically, even offline
• Approval flow: developers request, admins approve
• Fleet inventory: see what MCP servers your team runs (opt-in with consent)
• Compliance evidence: OWASP MCP Top 10 coverage report for audits

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What It Checks

MCP Security Guard discovers servers from every place AI clients load them: user, local and project scope, servers shipped inside installed plugins, claude_desktop_config.json, Claude Desktop extensions, organization-managed managed-mcp.json, other clients on the machine (Cursor, VS Code, Windsurf), and claude.ai connectors you've used.

It scans everything a server puts into the AI's context: tools, server instructions, prompts, resources and resource templates.

Everything runs locally. Nothing is sent anywhere unless you opt in.

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OWASP MCP Top 10 Coverage

Every finding is tagged with its OWASP MCP Top 10 id, in reports and in SARIF.

| MCP09 | Shadow MCP Servers | ✅ Discovery across user, project, local, plugin and Claude Desktop configs; approved-server policy enforced in audits, CI and at session st