MCP config security checker

Paste an MCP client config (mcp.json, .cursor/mcp.json, claude_desktop_config.json, .vscode/mcp.json or .claude.json). The checker looks for the mistakes behind real incidents, and gives a fix for each.

Nothing leaves your browser. The check is plain JavaScript on this page: no request is made with your config. Secrets in findings are shortened to a prefix. It is a static check of one file; it cannot tell you whether a server's code is trustworthy. See the checklist for what to do beyond it.

What it checks

  • Secrets in the file: token-shaped values and secret-named variables written inline, headers, arguments and query strings.
  • Unpinned servers: npx, bunx, uvx, pnpm dlx without an exact version, and mcp-remote older than 0.1.16 (CVE-2025-6514).
  • Transport and launch: http:// to a remote host, shell wrappers and download-and-run pipelines.
  • Reach: auto-approve lists, a filesystem server rooted at / or your home directory, privileged or root-mounting containers.
  • Dynv's MCP flags: --allow-reveal, wildcard --allow-keys, token creation and process admin.