The team behind Ethereum’s Layer 2 solution Base has released a report on two network outages that occurred on June 25 and 26. The block production halt was caused by a bug in the sequencer logic.
After a transaction failed to process, the mechanism incorrectly saved the system’s internal state, resulting in an invalid block.
The first incident lasted 116 minutes, and the second lasted 20 minutes. During these periods, the network stopped producing new blocks, transactions were not added to the blockchain, and the queue of unconfirmed operations overflowed, causing users to encounter errors when sending new transactions.
The team emphasized that user funds were not affected and remained secure.
What Happened
According to the report, the issue arose after a transaction failed. The sequencer did not clear the temporary state (journal state), leading to an incorrect fee calculation for the next valid transaction. This resulted in a block with an incorrect state transition, which other network nodes could not accept, halting block production entirely.
After implementing a fix, developers encountered a second issue: a “race condition” during the sequencer cluster restart, which prevented nodes from quickly synchronizing. This problem caused the second, shorter outage the following day.
Base’s Response
Following the incident, the Base team pledged to enhance stress testing and protocol fuzzing to identify unusual transaction processing scenarios in advance.
Additionally, developers plan to improve network monitoring and implement a “graceful recovery” mechanism to restore network operations more swiftly after similar outages.
Earlier, in February, the Base team announced a transition from the Optimism technology stack to its own unified network architecture.
