When Flatpak exports an application's Desktop Entry and D-Bus Service files, it rewrites Exec= to go
through the flatpak run wrapper and removes a small handful of known-dangerous keys. All other keys are
passed through unmodified.

Both file formats allow arbitrary vendor-extension keys, and desktop environments and D-Bus daemons act on
many of them. A malicious application can exploit this to interact with host functionality in ways the
sandbox is intended to prevent.

https://github.com/flatpak/flatpak/security/advisories/GHSA-v64f-hrwr-j4vh