Sui Mainnet Restores Service After 6‑Hour Stall Caused by Validator Crash Bug

Sui, a Layer-1 blockchain developed by Mysten Labs, resumed normal operations Thursday after its mainnet stalled for a little more than six hours because of a validator crash bug introduced in the 1.72 software release. The halt stopped the network from processing blocks normally, leaving on-chain transactions effectively unable to finalize until validators coordinated a software upgrade.

Sui’s official status page first acknowledged the incident on May 28 at 7:15 a.m. PDT, saying, “Investigating – We are currently investigating this issue.” At 7:36 a.m. PDT, the project said, “Identified - The issue has been identified and a fix is being implemented.” By 12:40 p.m. PDT, Sui posted, “Monitoring — Fix is rolling out to validators.” At about 1:31 p.m. PDT, the final update said, “Update - >2/3 of stake have upgraded to the fix, network is online.” Based on those timestamps, the outage lasted about 6 hours and 17 minutes from the first public acknowledgment to the online update.

Sui’s status reporting and multiple independent accounts citing the team said the outage was caused by a validator crash bug introduced in version 1.72, reportedly tied to gas-charging logic, the code that calculates and applies transaction fees. Recovery depended on validators — the network participants that help keep the blockchain running — installing a patched release and restoring enough upgraded stake to resume operations.

Repository records show that a patched binary was published during the recovery effort. GitHub lists a mainnet-v1.72.3 release on May 28, with the releases page showing it at 20:01, providing public evidence that a new version was made available as validators worked to bring the network back.

The outage had immediate market and operational effects. During a network stall, transactions may be submitted but cannot be finalized on-chain, meaning users and services do not get the normal assurance that transfers or other actions have been completed. Independent coverage, including CoinDesk, reported that SUI fell roughly 5% to 8% intraday during the disruption. Some service providers also paused SUI-related processing while the network was stalled. BitGo, the digital asset custodian, referenced the incident on its own status page and linked customers to Sui’s status updates.

Sui’s materials and press coverage described the event as a safety-preserving halt rather than a state corruption incident. According to Sui’s status reporting and coverage of the outage, there were no reported certified state forks — conflicting finalized versions of the ledger — and no reported user fund losses tied to the incident.

The disruption also adds to questions around reliability. Sui launched its mainnet in May 2023 and has experienced other multi-hour outages, including a roughly six-hour stall in January 2026 that the project later attributed to a consensus-related bug, and a roughly two-hour outage in November 2024. This latest halt follows that pattern of periodic operational disruptions, even as the network recovered without reported fund losses.

A fuller incident review is expected in the coming days, according to press reports. For now, the episode underscored how a software bug in a validator release can freeze activity on a live blockchain until enough operators deploy a fix and restore the network to service.