An issue was discovered in Ampache through 3.9.1. A stored XSS exists in the localplay.php LocalPlay "add instance" functionality. The injected code is reflected in the instances menu. This vulnerability can be abused to force an admin to create a new privileged user whose credentials are known by the attacker.
https://www.tarlogic.com/en/blog/vulnerabilities-in-ampache/
https://lists.debian.org/debian-lts-announce/2019/11/msg00008.html