Sui’s mainnet experienced three separate outages across May 28 and 29 after a v1.72 software release exposed critical bugs in gas-charging logic, according to a post-mortem published by the Sui Foundation on June 1.
The first outage began at approximately 7 a.m. PT on May 28 and lasted seven hours. Validators, the computers that process transactions and maintain network consensus, crashed when handling mixed-payment transactions that lacked sufficient funds. The network was restored at 1:30 p.m. PT with an interim fix.
The Sui Foundation described the interim solution as “a known issue with a low probability of causing a halt.” That characterization proved premature. A second outage began at 5 a.m. PT on May 29, triggered by a masked variant of the insufficient-funds bug. Validators adopted a robust fix at 9:40 a.m. PT that addressed the underlying gas-charging logic flaw.
A third outage then occurred during validator restart as part of the epoch change process. This incident stemmed from a latent bug in the on-chain randomness protocol, which produces unpredictable values that all validators must agree on. Applications dependent on chance, such as lotteries, games, and NFT mints, require this protocol to function. The bug failed to persist the disabled state of on-chain randomness to disk, causing a six-hour stall.
The v1.72 release introduced a new address-balance feature. Coin objects in Sui represent distinct digital assets with individual IDs that can be combined for transactions. The new functionality exposed edge cases in how validators charged gas fees during these operations.
SUI token price declined 8 percent during the cascade of outages, reaching a low of $0.90. The token fell 19 percent over the full week.
The Sui Foundation confirmed that no user funds were lost and no committed transactions were reverted. This marks the third major reliability incident since Sui’s mainnet launch in 2023, following a transaction scheduling bug in November 2024 that lasted two hours and a consensus divergence in January 2026 that lasted six hours.
