Here is a more detailed explanation of the exploit.
The Pepaire-Bueno brothers exploited a bug in MEV-boost's code that allowed them to preview the content of blocks before they were officially delivered to validators, according to the indictment.
The brothers created 16 Ethereum validators and targeted three specific traders who operated MEV bots, the indictment said. They used bait transactions to figure out how those bots traded, lured the bots to one of their validators which was validating a new block and basically tricked these bots into proposing certain transactions. [...]
So hardly an attack on any core system of cryptocurrencies.