In Telegram WebK before 2.0.0 (488), a crafted Mini Web App allows XSS via the postMessage web_app_open_link event type.
https://www.openwall.com/lists/oss-security/2024/04/28/4
https://medium.com/%40pedbap/telegram-web-app-xss-session-hijacking-1-click-95acccdc8d90