Starknet experienced a brief mainnet outage this Monday, and the official team subsequently released an incident analysis report. The issue stemmed from a state inconsistency between the execution layer (blockifier) and the proof layer — specifically, in certain cross-function call and rollback scenarios, the execution layer incorrectly recorded state writes that should have been revoked, ultimately causing transaction execution errors. These affected transactions never received finality confirmation from L1. The incident triggered a chain reorganization, impacting approximately 18 blocks.

This event highlights the fragility of L2 architecture in managing complex states. Coordination issues between the execution layer and the proof layer may seem low probability, but once they occur, they can easily cause chain reactions. The good news is that Starknet's official team promptly identified the problem and published an analysis, and subsequent fixes and risk control upgrades are worth paying attention to. For users, this also serves as a reminder of the risk awareness needed when participating in emerging L2 networks.