Incorrect File Permissions in Nagios XI 5.7.5 and earlier and Nagios Fusion 4.1.8 and earlier allows for Privilege Escalation to root. Low-privileged users are able to modify files that are included (aka sourced) by scripts executed by root.
https://www.nagios.com/downloads/nagios-xi/change-log/
https://skylightcyber.com/2021/05/20/13-nagios-vulnerabilities-7-will-shock-you/