Improper neutralization of file names, conversation names and board names in Nextcloud Server 16.0.3, Nextcloud Talk 6.0.3 and Nextcloud Deck 0.6.5 causes an XSS when linking them with each others in a project.
A missing check in the Nextcloud Server prior to version 15.0.1 causes leaking of calendar event names when adding or modifying confidential or private events.