Hikka is a Telegram userbot. A vulnerability affects all users of versions below 1.6.2, including most of the forks. It allows an unauthenticated attacker to gain access to Telegram account of a victim, as well as full access to the server. The issue is patched in version 1.6.2. No known workarounds are available.
https://github.com/hikariatama/Hikka/security/advisories/GHSA-vwpq-wm8w-44wf
https://github.com/hikariatama/Hikka/commit/9a0e4b1b387ef828c345c43d990421d5afcff5f6