Wu said that the Flow Foundation issued a statement stating that on December 27, an attacker exploited a vulnerability in the Flow execution layer to transfer approximately $3.9 million worth of assets off-chain before the validator execution coordination was halted. The attack did not affect the balances of existing users. All user deposits remain intact. The protocol fix has been developed and released, and node operators are coordinating the deployment of this upgrade. The network will roll back to a checkpoint before the vulnerability was exploited to remove unauthorized transactions.