Vulnerability allows cross-browser tracking in Chrome, Firefox, Safari, and Tor
> In a quick search of the web, we couldn’t find any website actively exploiting it but we still felt the need to report it as soon as possible.I've seen popup-based exploits on less-legal websites (e.g. torrents, keygens, illegal streaming of live sports and/or movies) a few times over the years. I'm unsure if they're executing this specific exploit though.