WWBN AVideo, in versions up to and including commit c3edcc274c389816d434acadac07ee78eaf330c1, contains a stored cross-site scripting vulnerability. objects/categoryAddNew.json.php passes the POST parameters "name" and "iconClass" to Category::setName() and Category::setIconClass(), which store the values without sanitization (setName only truncates to 45 characters). The category name is later echoed as HTML text and iconClass is echoed into a class attribute in view/modeYoutubeBottom.php and in Gallery cards (plugin/Gallery/functions.php). When the CustomizeUser option usersCanCreateNewCategories is enabled, any authenticated user with canUpload permission (granted by default via self-registration) can create a category containing a JavaScript payload; the payload then executes in the browser of any visitor, including administrators, who views a watch page or gallery entry for a video assigned to that category, allowing actions such as authenticated requests with the victim's session. The issue was unpatched at the time of reporting.