>> Ultimately, we achieve a out-of-bounds read anywhere in the address space of Safari's rendering process.

> So, in my opinion, this is a Safari vulnerability: they hold Site Isolation wrong.

Previously, something I would normally consider a Safari specific bug (IndexedDB storage not being isolated to its owning web page) also made it into Gnome Web and various other WebKit browsers. Site Isolation is enabled on other browsers but as an outsider I have no idea if that is normally handled by WebKit or by the surrounding framework.

It looks like Gnome Web/Epiphany is safe at least: https://gitlab.gnome.org/GNOME/epiphany/-/merge_requests/448 but there are plenty of WebKit implementations out there, such as cars and video game consoles.