We scanned 8,400+ MCP servers for security issues -- here's what we found

[AgentSeal]

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We built https://agentseal.org, an open-source security scanner for MCP servers, and ran it against every public MCP server we could find. Some stats from the registry:

• 8,400+ servers analyzed with static + LLM-powered analysis
• 87 security issues filed on GitHub repos (including GitHub's own MCP server, AWS AgentCore, Daytona, Chrome DevTools)
• 5 maintainers shipped fixes within days of our reports
• Common findings: missing input validation, annotation mismatches (readOnlyHint on mutating tools), command injection via unsanitized args, unauthenticated WebSocket endpoints

The full registry is browsable at https://agentseal.org -- every server gets a trust score with detailed findings breakdown.

CLI tools (OSS):

• scan-mcp -- scan any MCP server config (stdio or SSE)
• scan-repo -- scan a GitHub repo for MCP security issues
• guard -- runtime protection layer for MCP connections

Happy to answer questions about MCP security patterns we've seen across the ecosystem.

Relevant Links

GitHub: https://github.com/agentseal
PyPI: pip install agentseal | npm: npm install agentseal
We also published a https://agentseal.org/blog on exploiting 6 MCP servers (68K combined GitHub stars) with working PoCs.