This vulnerability allowed a site to enter fullscreen, after a user click, without a full-screen notification (toast) appearing. Without this notification, users could potentially be misled about what site they were on if a malicious site renders a fake UI (like a fake address bar.)

This vulnerability allowed a site to enter fullscreen, after a user click, without a full-screen notification (toast) appearing. Without this notification, users could potentially be misled about what site they were on if a malicious site renders a fake UI (like a fake address bar.)