Improper escaping of a textarea custom field's contents in the Update Issue page (bug_update_page.php) allows an attacker to inject HTML and, if CSP settings permit, execute arbitrary JavaScript when the page is loaded.
Impact
Session theft leading to admin account takeover, full project data access.
Precondition: A textarea-type custom field must be configured for the project
Attacker: Authenticated user with bug report permission (low privilege)
Victim: Any user viewing the bug edit form, including administrators
Patches
5fec0f448b7a7d7d539a6adb6dccceac4e4e4ab7
Workarounds
The default Content-Security Policy will block script execution.