Sui's mainnet suffered three separate outages over May 28-29 after its 1.72 upgrade exposed edge cases in gas charging and validator restart logic. The network went down twice on Tuesday and once on Wednesday, with total downtime stretching across nearly 12 hours. No user funds were at risk and no committed transactions were reverted, according to the Sui Foundation.
Gas-charging bug triggers first two outages
The first outage began around 7:00 AM PT on May 28 and lasted until 1:30 PM PT. The second followed the next morning, from 5:00 AM to 8:30 AM PT on May 29. Both were caused by a gas-charging bug in the hybrid address balance/coin gas path that led to an underflow condition. An interim patch was deployed to avoid gas smashing when a transaction is cancelled with InsufficientFundsForWithdraw, but that fix had a weakness: the underflow could still occur under multiple cancellation reasons.
Third outage linked to DKG persistence failure
The third outage, from 1:30 PM to 7:20 PM PT on May 29, stemmed from a randomness-state bug. The problem was that the verdict from a failed distributed key generation (DKG) round was not written to disk. Validators essentially forgot the failure happened, leaving the epoch stuck and unable to progress. The fix involved persisting DKG status across restarts and adding a mechanism to close the stuck epoch at a coordinated point.
Foundation calls for stronger resilience measures
The Sui Foundation stated that the postmortem showed the need for further investment in end-of-epoch resilience and more rigorous gas charging logic. The foundation did not provide a timeline for implementing broader improvements. At the time of the report, SUI was trading at $0.8798, down from levels seen before the outages.
Questions remain about whether further patches will be required and how the network will prevent similar cascading failures during future upgrades.
