Stored XSS => community.ubnt.com

Summary

Due to an error on the user input validation process, it was possible to create posts in some forums on community.ubnt.com with arbitrary HTML code, an especially crafted message could inject Javascript code on the page, resulting in stored XSS.

A Stored XSS issue Was Discovered in ubnt Community. The specially crafted XSS payload can be Posted as Comment under Any Post, The payload Executes and Collect certain User Information and Can be Further Used to Exploit for Account takeover Issue, Thanks to @ubnt-rubens For Guidances on the issue as it wasIn out of Scope subdomain, & Thanks @ubnt for The Bounty