Base mainnet will undergo the Optimism Superchain U16A upgrade on October 8.

According to Jinse Finance, Base Build announced that the Base mainnet will undergo the Optimism Superchain U16A upgrade from 1:00 to 3:00 on October 8 (UTC+8). This will temporarily invalidate pending withdrawals from the Base mainnet to Ethereum L1, while deposits and on-chain activities will proceed as usual. Users should ensure that all pending withdrawal transactions are completed before 1:00 on October 8.