CVE-2017-5226 is a issue with bubblewrap that allows a program running in a sandbox to excape and get the same privileges as a the parent process. I recently discovered this by mistake and it is fairly concerning to me. I believe it applies to Flatpak as Flatpak uses bubblewrap under the hood.

Many people like to boast about how secure and private flatpak and some even run untrusted software in it. However, the reality is that there hasn’t been a lot of testing and the fact that this CVE still exists but isn’t well known is concerning.

The reason it wasn’t patched is that it is really hard to properly fix. The work around is to call bubblewrap with the --new-session flag as this effectively prevents the excape. However, this breaks interactive programs such as htop. Also the bubblewrap team believes this is a issue that should be solved downstream as this CVE is technically not a CVE in the traditional sense.

I think it is still better to run flatpak over non flatpak but it is something to be aware of

Edit:

It doesn’t apply to flatpak as it is patched in 1.3.1and higher https://github.com/flatpak/flatpak/security/advisories/GHSA-7gfv-rvfx-h87x

Basically this is a communication and people problem not a technical one

Edit2:

This isn’t exploitable on modern systems with 6.1 or newer with the way most distros compile the kernel