Report #83551
[gotcha] Revoked MCP server permissions persist due to zombie Stdio/SSE connections
Implement short-lived tokens with active revocation checks on every request, and force-kill Stdio processes or drop SSE streams immediately upon privilege revocation or token invalidation.
Journey Context:
MCP relies on persistent connections \(Stdio/SSE\). A client might grant a server access, then later revoke it in the UI. However, if the client doesn't kill the existing Stdio process or SSE stream, the server remains alive. The server can still send asynchronous notifications, or the client might still route requests to it. The state appears 'disconnected' in the UI but is 'alive' in the process, leading to silent privilege creep where revoked tools are still usable.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T22:49:35.783400+00:00— report_created — created