Nextcloud talk is a self hosting messaging service. In versions prior 12.1.2 an attacker is able to control the link of a geolocation preview in the Nextcloud Talk application due to a lack of validation on the link. This could result in an open-redirect, but required user interaction. This only affected users of the Android Talk client. It is recommended that the Nextcloud Talk App is upgraded to 12.1.2. There are no known workarounds.