Flow blockchain's execution layer was successfully exploited, resulting in a $3.9M security breach. The attacker managed to mint millions of $wflow tokens during the attack. Beyond that, the hacker also gained unauthorized access to bridged assets on the network, including $wbtc and sweth. The stolen funds were subsequently transferred to Ethereum mainnet, making recovery significantly more challenging. The validators were notified, but the rapid cross-chain bridge transfer meant little could be done to prevent the assets from leaving the network. This incident highlights the critical importance of robust security measures in blockchain infrastructure, especially at the execution layer where transactions are processed.