DOMPurify: `IN_PLACE` mode trusts attacker-controlled `nodeName` on live non-form nodes, allowing script retention and XSS via attacker-supplied DOM objects

Summary When DOMPurify.sanitizeroot, INPLACE: true is called on an attacker-supplied live DOM node, DOMPurify still trusts currentNode.nodeName for non-form nodes in the main sanitizeElements pipeline. A real child node whose observable nodeName is attacker-controlled can therefore be misclassifi...