MetaMask Security Breach Triggers Ethereum Validator Exits Surge

A security breach has led to a surge in Ethereum validator exits, causing a nine-month high backlog for stakers trying to exit. Approximately 17,000 MetaMask-operated validators holding around 523,000 ETH were proactively exited after an analysis found that transaction-fee rewards from 18 of 19 validators had been diverted to an address funded through Tornado Cash.

The attacker appears to have captured only about 0.36 ETH. Onchain security researcher Kaden noted the bigger concern is how the attacker gained enough access to alter fee recipients and whether that access extended to validator signing keys, which could trigger slashable behavior.

MetaMask has not confirmed those figures or disclosed the cause of the incident, instead stating part of its infrastructure had been compromised. The company exited affected validators as a precaution while working with clients, partners, and security advisers, claiming it had identified no immediate threat to MetaMask wallets.