Starknet releases post-mortem analysis report: blockifier bug causes transaction processing errors

Techub News reports that Starknet has released a post-mortem analysis report regarding the brief mainnet outage on January 5th. Starknet stated that the core issue was a blockifier bug which caused it to incorrectly process transactions. Specifically, under a specific combination of cross-function calls, variable writes, rollbacks, and rollback captures, the blockifier erroneously remembered state write operations within a rolled-back function as valid, thereby triggering transaction execution errors. However, thanks to Starknet's prover layer mechanism, this erroneous execution was never finalized on the L1 layer.

This incident triggered a block reorganization, rolling back approximately 18 minutes of on-chain activity. This marks the second major outage since 2025, following a previous incident in September where a sequencer bug caused an outage of over 5 hours and rolled back about 1 hour of on-chain activity.