The Sui Foundation team released a report detailing the causes of three mainnet halts that occurred on May 28 and 29. The incidents were linked to vulnerabilities that emerged following the software upgrade to version 1.72.
The first network halt lasted approximately six and a half hours. According to the developers, it was triggered by a bug in the new Address Balances feature, which caused failures in the gas deduction mechanism. Transactions were canceled due to insufficient funds, yet the network continued to spend them, creating negative balances. This led to a failure during the validators’ account reconciliation stage.
The second disruption occurred due to the implementation of an interim fix for the first error. The team acknowledged that they were aware of the “low probability” of a halt due to the patch but consciously took this risk for the quick restoration of the blockchain’s operation.
The third halt was caused by a completely different, previously unknown issue. When restarting nodes to install the final fix, a hidden bug related to saving random number generation settings between epochs was triggered. Due to the error, validators were unable to record the necessary data and close the epoch, paralyzing the network for the third time.
The Sui Foundation emphasized that user funds remained completely secure, and confirmed transactions were not rolled back after the network was restored. All errors have now been fixed, and the network is operating normally.
Project representatives also noted that they successfully used AI agents to expedite diagnostics and collect metrics from validator logs during the incidents.
Back in January, Sui also experienced a six-hour outage.