void Element::cancelFocusAppearanceUpdate()
{
    if (hasRareData())
        elementRareData()->setNeedsFocusAppearanceUpdateSoonAfterAttach(false);
    if (document()->focusedNode() == this)
        document()->cancelFocusAppearanceUpdate();
}

This vulnerability category highlights issues in resource management where failures to properly release memory, file handles, or other resources can degrade system performance or enable denial-of-service conditions.