OPNsense 19.1 Reflected XSS via diag_backup.php

OPNsense 19.1 contains multiple cross-site scripting vulnerabilities in the diag_backup.php endpoint that allow attackers to inject malicious scripts through multiple parameters including GDrive_GDriveEmail, GDrive_GDriveFolderID, GDrive_GDriveBackupCount, Nextcloud_url, Nextcloud_user, Nextcloud_password, Nextcloud_password_encryption, and Nextcloud_backupdir. Attackers can submit POST requests with script payloads in these parameters to execute arbitrary JavaScript in the context of authenticated administrator sessions.