tl;dr
Coinbase's Ethereum layer-2 network, Base mainnet, stalled at block 33,792,704 for over 19 minutes due to a technical issue causing an "unsafe head delay," halting block production, deposits, withdrawals, and flashblocks. This delay indicates a failure in sequencer operation, block propagation, or c...
According to BaseScan and OKLink, Coinbase's Ethereum layer-2 network, the Base mainnet, has experienced a technical issue causing the chain to stall at block height 33,792,704, with no new blocks generated for at least 19 minutes. The official status page confirmed the disruption, noting that block production, deposits, withdrawals, and flashblocks are all impacted. The incident is described as an "unsafe head delay."
An unsafe head delay refers to a situation where the most recent, yet not finalized, block on the blockchain (known as the unsafe head) is failing to progress normally. This delay typically points to a significant failure in sequencer behavior, block propagation, or consensus mechanisms. In layer-2 rollups like Base, which relies on Optimism’s OP Stack, a centralized sequencer batches transactions and posts them to Ethereum. When this sequencer stalls, no new blocks can be created, potentially freezing the entire chain, especially since Base currently lacks fallback mechanisms or multiple decentralized sequencers.
The root causes of the problem may include sequencer failure, where the centralized sequencer crashes or encounters an issue, network congestion or RPC failures affecting the backend nodes, or bugs related to consensus and finality such as errors in fork-choice logic, timestamp validation, or state transitions. Early indications suggest this is more likely a technical bug rather than an exploit or critical security breach.
This outage highlights the risks associated with centralization in layer-2 rollup designs. As Base is powered by Coinbase, there are heightened expectations for uptime and reliability, particularly from consumer-facing applications and financial institutions. Users are advised to avoid deposits and contract calls until block production resumes and a detailed incident report is released. This event serves as a reminder that even rollups with strong institutional support are vulnerable to infrastructure-level disruptions.