MagicMirror² is an open source modular smart mirror platform. Prior to 2.37.0, the ADD_CALENDAR handler in defaultmodules/calendar/node_helper.js accepts an attacker-controlled URL, authentication data, and selfSignedCert setting through the unauthenticated Socket.IO namespace /calendar. The handler passes these fields to CalendarFetcher, causing a server-side request without SSRF validation and optionally disabling TLS verification. When the response is valid iCal, CALENDAR_EVENTS returns parsed event data to the attacker, allowing internal-service response data to be exfiltrated; other responses still provide a blind request and timing primitive. This issue is fixed in version 2.37.0.