vBulletin 5.x through 5.5.4 allows remote command execution via the widgetConfig[code] parameter in an ajax/render/widgetphp routestring request.
vBulletin 5.5.4 through 5.6.2 allows remote command execution via crafted subWidgets data in an ajax/render/widgettabbedcontainertabpanel request. NOTE: this issue exists because of an incomplete fix for CVE-2019-16759.