Telegram Messenger is a communication app that allows you to create encrypted chats and phone calls with other users over the Internet. This program describes itself as being a secure and private communication app, but a researcher has shown that in its default config it would allow a user’s IP address to be leaked when making calls. […]

from https://www.bleepingcomputer.com/news/security/telegram-leaks-ip-addresses-by-default-when-initiating-calls/