In FusionPBX up to 4.5.7, the file app\contacts\contact_times.php uses an unsanitized "id" variable coming from the URL, which is reflected in HTML, leading to XSS.
https://resp3ctblog.wordpress.com/2019/10/19/fusionpbx-xss-7/
https://github.com/fusionpbx/fusionpbx/commit/bcc75d63aa5b721f699a2b416425943ad7707825