Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server

影響: pip:mcp >= 2.0.0, < 2.2.0 → 2.2.0, pip:mcp >= 1.10.0, < 1.30.0 → 1.30.0

In affected versions, the SDK's server-side bearer authentication had no way to check that a token was issued for your server (its audience). Where one authorization server issues tokens for several services, a valid token for another service was also accepted by your MCP server. Am I affected? Yes, if your HTTP server uses the SDK's bearer authentication (auth=AuthSettings(...) with token_verifier=), its authorization server also issues tokens for other services, and your TokenVerifier does no…

GitHub Advisory Databaseで読む

2026/10/28 06:06、GitHub Advisory Databaseが「Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server」を公開しました (種別: 脆弱性アドバイザリ)。重大度は「警告」(medium) です。関連する技術: Python。CVE: CVE-2026-116684。