Mantis Bug Tracker (MantisBT) is an open source issue tracker. From 1.0.0 to 2.28.1, lack of validation of filter_target parameter on return_dynamic_filters.php (normally used as an AJAX in View Issues Page) allows an attacker to inject arbitrary HTML if the target is a TEXTAREA custom field. This vulnerability is fixed in 2.28.2.
Improper Neutralization of Input During Web Page Generation The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.