Firejail discusses this briefly in their X11 guide: The sandbox replaces the regular X11 server with Xpra or Xephyr server. This prevents X11 keyboard loggers

Firejail discusses this briefly in their X11 guide: The sandbox replaces the regular X11 server with Xpra or Xephyr server. This prevents X11 keyboard loggers and screenshot utilities from accessing the main X11 server. https://firejail.wordpress.com/documentation-2/x11-guide https://firejail.wordpress.com/documentation-2/x11-guide It's not a common issue, but obviously a security concern to make it so easy for keyloggers to record your keypresses or screen. I currently prefer X11 to Wayland, and I'd love if this problem was possible to address without Firejail. I use Firejail for other sandboxing tasks, but sandboxing X11 is too impractical.