Pretty sure this EXTREMELY rare, once in a decade exploit isn't something you have to be afraid of with every single game out there.

If you're this afraid of having your computer taken over, then you probably shouldn't use a computer to begin with. Because these exploits aren't just on the software level, but can be exploited on hardware level too, sometimes intentionally put in there in cooperation with national security agencies.

Microsoft patches these exploits in Windows all the time.

The only thing that made the Dark Souls 3 exploit unique is that it's a game this time, not an OS. Why would this game even have such code to begin with, that's the real question.

It's fairly safe to say that Valheim does not have such an exploit.