Low · published September 29, 2026
Flatpak passes through arbitrary vendor-extension keys unmodified when exporting an application's Desktop Entry (.desktop) and D-Bus Service (.service) files, instead of validating against an allowlist. A malicious Flatpak app can use this to cause denial of service (e.g. forced application restart loops) or to influence host D-Bus/systemd activation behavior beyond what the sandbox is intended to permit.