

The browser can’t create unprivileged namespaces because Flatpak blocks access to namespace creation. This DOES interfere with an important method of sandboxing used by browsers on Linux. It makes site isolation weaker, which could allow an attacker from a malicious site to steal information from any open tab, or possibly escape the sandbox. Browser sandboxes are multilayered for a reason, one less layer makes exploitation exponential easier. The Firefox Flatpak is official, but that doesn’t mean it is safe. Flatpak sandboxing is substantially less strong than a browser’s isolation strategy This because Flatpak is a general purpose sandbox mostly meant for making distribution of software easy by providing an identical environment across all Linux distros, not for rigid security. Browser’s provide a more fine grained sandbox that is designed around the threat model that the website is compromised/malicious and is attempting to hack you, since websites are effectively just apps. Don’t use Flatpak’d browsers at all, or the very least not as your default.






You don’t have to sandbox he browser with Bubblejail if you don’t want. I was only suggesting it and providing instructions in case you wanted an extra layer of isolation.