CVE-2026-34463: MantisBT is Vulnerable to Stored HTML Injection/XSS in Clone Issue Form

When cloning an issue originating from a Project other than the current one, the clone form (bug_report_page.php) prepends the source Project name before the category selector without proper escaping, allowing an attacker able to to inject HTML if they can set the Project’s name (which typically requires manager or administrator access level).