Nagios XI versions prior to 2024R1 are vulnerable to cross-site scripting (XSS) via the Graph Explorer component. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.
Nagios addresses this vulnerability as "It was discovered that Nagios XI's graphexplorer component was vulnerable to an XSS vulnerability" and "Fixed an XSS vulnerability in the graphexplorer component."