Only the latest 3.x release receives security fixes. Please upgrade before reporting.

Please do not open public issues for security problems.

Report privately via GitHub private vulnerability reporting, or email security@kriasoft.com.

Include the affected version, runtime (Node.js, Bun, or Deno), steps to reproduce, and the impact you observed. We aim to acknowledge reports within a few days and will keep you updated until a fix is released. With your permission, we'll credit you in the advisory.

Examples of issues we want to hear about:

• Leaking authorization codes, tokens, or client secrets (logs, error pages, files, network)
• Bypassing state validation or PKCE, or accepting a callback that should be rejected
• Credential files (fileStore) readable or replaceable by other local users
• HTML or script injection in the callback pages, or provider text echoed where the docs say it isn't
• An unsafe authorization URL (neither https: nor loopback http:, or with a fragment or credentials) reaching the launcher
• The callback server accepting connections it shouldn't, or staying reachable after shutdown

Vulnerabilities in the OAuth provider or in the MCP SDK (@modelcontextprotocol/client) should be reported to those projects.