An issue was discovered in Joomla! before 3.9.7. The update server URL of com_joomlaupdate can be manipulated by non Super-Admin users.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2019-4348
https://developer.joomla.org/security-centre/785-20190603-core-acl-hardening-of-com-joomlaupdate