Cross-site scripting (XSS) vulnerability in the _renderVarInput_number function in horde/framework/Core/lib/Horde/Core/Ui/VarRenderer/Html.php in Horde Groupware before 5.2.12 and Horde Groupware Webmail Edition before 5.2.12 allows remote attackers to inject arbitrary web script or HTML via vectors involving numeric form fields.