The Sui Foundation team published a report detailing the reasons behind three halts of the blockchain's mainnet that occurred on May 28 and 29. The incidents were linked to vulnerabilities that emerged after upgrading the software to version 1.72.
The first network halt lasted about six and a half hours. According to the developers, it was caused by a bug in the new Address Balances feature, which disrupted the gas fee deduction mechanism. Transactions were being canceled due to insufficient funds, yet the network continued to process them, resulting in negative balances. This led to failures during the validators' reconciliation process.
The second failure occurred due to the implementation of a temporary 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 the risk to quickly restore the blockchain's functionality.
The third outage was triggered by a completely different, previously unknown issue. When restarting nodes to apply the final fix, a hidden bug related to the preservation of random number generation settings across different epochs was activated. Due to this error, validators were unable to finalize the necessary data and close the epoch, which paralyzed the network for the third time.
The Sui Foundation emphasized that user funds were completely safe, 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 utilized AI agents to expedite diagnostics and gather metrics from validator logs during the incidents.
It’s worth mentioning that Sui also experienced a six-hour outage in January.