Multiple cross-site scripting (XSS) vulnerabilities in Dolibarr 3.1.0 RC and probably earlier allow remote attackers to inject arbitrary web script or HTML via the PATH_INFO to (1) index.php, (2) admin/boxes.php, (3) comm/clients.php, (4) commande/index.php; and the optioncss parameter to (5) admin/ihm.php and (6) user/home.php.