Nextcloud Talk is a fully on-premises audio/video and chat communication service. Password protected shared chats in Talk before version 9.0.10, 10.0.8 and 11.2.2 did not rotate the session cookie after a successful authentication event. It is recommended that the Nextcloud Talk App is upgraded to 9.0.10, 10.0.8 or 11.2.2. No workarounds for this vulnerability are known to exist.
A bug in Nextcloud Server 15.0.2 causes pending 2FA logins to not be correctly expired when the password of the user is reset.
Nextcloud Server before 11.0.3 is vulnerable to an improper session handling allowed an application specific password without permission to the files access to the users file.