Nagios Core 4.4.2 has XSS via the alert summary reports of plugin results, as demonstrated by a SCRIPT element delivered by a modified check_load plugin to NRPE.
{ "availability": "No subscription required", "ubuntu_priority": "low", "binaries": [ { "binary_version": "4.3.4-3", "binary_name": "nagios4" }, { "binary_version": "4.3.4-3", "binary_name": "nagios4-cgi" }, { "binary_version": "4.3.4-3", "binary_name": "nagios4-common" }, { "binary_version": "4.3.4-3", "binary_name": "nagios4-core" }, { "binary_version": "4.3.4-3", "binary_name": "nagios4-dbg" } ] }