The sequencer vulnerability caused two crashes in a row. Base's review came quickly enough, but 116 minutes + 20 minutes of chain downtime left a significant psychological shadow on users.

Wu learned that Base released a post-mortem report on two mainnet outage incidents on June 25 and 26, stating that both events were caused by the same Sequencer block construction logic vulnerability, which resulted in blocks containing invalid state transitions, leading to network outages of approximately 116 minutes and 20 minutes, respectively. Base stated that on-chain funds were not affected, the vulnerability has been fixed, and it plans to further enhance protocol fuzz testing, load testing, and network recovery mechanisms to reduce the risk of similar incidents recurring.