What DS3 exploit?

Never heard of a single case where players were able to steal confidential information from another just because they were on the same server.

Edit: Ah, you were referring to Dark Souls it seems. Anyway, this game has nothing to do with Valheim, it uses another engine. In general, just because players can steal information in one game, doesn't mean that they can do it in another game. I understand your concerns tho.