Nextcloud: Username Enumeration

Hi, it is possible to determine the existence of a user account. It reveals username which can open new attack vectors. Version: Nextcloud 16.0.3 Request for existing account: GET /avatar/admin/80?v=-472 HTTP/1.1 Host: localhost:8084 User-Agent: Mozilla/5.0 Macintosh; Intel Mac OS X 10.14; rv:68....