Is private key hacking/leaking online an additional attack surface for Ethereum under pos?

Obviously this is more a theoretical questions, but I just randomly started thinking about this today…In theory if some hacker got access to 50%+ of private keys belonging to the wallets attached to validators, wouldn’t the Ethereum network be under risk? Would the attacker have complete control over those validators in that case? Is this a new attack surface under pos as in pow you would physically need to access the hardware to control the miners?