Sui said its mainnet has resumed normal activity after three outages across May 28 and May 29, 2026, all tied to issues surfaced around the network’s v1.72 release. The Sui Foundation’s May 31 post-mortem attributed the first two halts to gas-charging crash bugs, while the third came from a separate validator randomness-state issue exposed during restarts.
The foundation said the first outage began at about 7:00 a.m. PT on Thursday, May 28, and ended around 1:30 p.m. PT. The second began at roughly 5:00 a.m. PT on Friday, May 29, and ended around 8:30 a.m. PT, while the third began at about 1:30 p.m. PT that Friday and ended near 7:20 p.m. PT. Sui said no user funds were at risk and no committed transactions were reverted when the network resumed.
Gas-Charging Bug Triggered the First Two Halts
The first two incidents were linked to Sui’s v1.72 address-balance feature, which introduced a new way for users to store funds and pay gas without relying only on coin objects. The bug appeared when hybrid gas payments interacted with insufficient-funds handling, causing a transaction marked as canceled to still affect gas accounting in a way that produced an underflow during balance reconciliation.
Sui said the first fix was an interim measure designed to restore network functionality quickly while a more durable patch was being developed. That interim fix carried a known low-probability halt risk, which the team accepted to bring the network back online; a variant of the same issue then triggered the second outage on Friday morning.
After the second halt, the core team proposed a more robust fix to validators by around 8:00 a.m. PT, and enough validators adopted it to bring the network back by about 9:40 a.m. PT, according to the technical section of the review. That timing slightly extends the operational recovery detail beyond the post-mortem’s summary window, which lists the second outage as ending around 8:30 a.m. PT.
Randomness-State Bug Caused the Third Outage
The third halt had a different root cause. When validators restarted to adopt the Friday morning fix, a latent bug in how randomness state was preserved across restarts was exposed, preventing the scheduled epoch change from completing properly.
Sui said its validators run a distributed key generation process at the start of each epoch to support the network’s random beacon. The issue occurred after randomness disabled itself as designed, but that failure state was not written to disk, leaving validators unable to complete the next epoch transition after further restarts.
The confirmed state is that validators have addressed the known gas-charging and randomness-state bugs, and network activity has resumed. The incident remains an upgrade-related reliability event rather than a funds-at-risk exploit, but it shows how a protocol release can expose adjacent systems such as gas accounting, validator restart handling and randomness coordination.