Nextcloud talk is a video & audio conferencing app for Nextcloud. In affected versions the talk app does not properly filter access to a conversations member list. As a result an attacker could use this vulnerability to gain information about the members of a Talk conversation, even if they themselves are not members. It is recommended that the Nextcloud Talk is upgraded to 14.0.9 or 15.0.4. There are no known workarounds for this vulnerability.