If you are using wireless mice and keyboards you should be aware of the risks. Also see this article at Computerworld.
At least Logitech provides a firmware update which fixes the problems:
The program also checks if there is an update needed at all. So I found out that even the Unifying Receiver of a new keyboard (K270), bought in January 2018, was still shipped with an outdated firmware.
Only when the update tools displays a message that all found devices are up to date, there is no risk.