In FusionPBX up to 4.5.7, the file app\sip_status\sip_status.php uses an unsanitized "savemsg" variable coming from the URL, which is reflected in HTML, leading to XSS.
https://resp3ctblog.wordpress.com/2019/10/19/fusionpbx-xss-3/
https://github.com/fusionpbx/fusionpbx/commit/a55f1cd5d8edd655058152e9acf212680d5b75f3