Sui Mainnet Crash: 3 Outages in 48 Hours Shook the Crypto World!

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Sui Foundation Explains Why the Mainnet Stopped 3 Times in 2 Days

Key Takeaways

  • Three Sui mainnet halts occurred between May 28-29, all traced to v1.72 upgrade.
  • Gas-charging bug caused halts 1 and 2, triggered by new Address Balances feature.
  • Emergency patch carried known risk, which materialized Friday morning as halt 2.
  • Third halt caused by randomness state not saving to disk during validator restart.

One Upgrade, Two Bugs, Three Outages

Last week, the Sui network experienced three outages within 48 hours. The Sui Foundation has since released a thorough explanation of what caused these issues. Essentially, a recent upgrade (version 1.72) included a new feature that unexpectedly clashed with the existing system for calculating transaction fees, and this wasn’t detected before it was launched. Unfortunately, each attempt to fix the problem ended up creating the conditions for a new one to occur.

As part of my research, I’ve been investigating a recent upgrade that introduced something called Address Balances. The idea was to let users store funds and pay for transactions in a new way, without relying on the standard coin system. While it looked good on paper, I discovered it actually revealed a problem with how the network processes canceled transactions – a tricky edge case we hadn’t anticipated.

The Gas Bug That Started Everything

As an analyst, I’ve been looking into a recent issue with how transactions are handled. The system *should* cancel one transaction if two try to use the same funds at the same time and there isn’t enough to cover both. However, we found a bug in what happened *after* the cancellation. Even though a transaction was flagged as canceled due to a lack of funds, the system still tried to deduct those funds during a process called ‘gas smashing’ – where multiple payment sources are combined before fees are applied. Essentially, it was trying to spend money that wasn’t there, even after acknowledging the insufficient balance.

As a researcher on the project, we discovered a negative balance where we anticipated zero, and unfortunately, this caused our validator nodes to crash. The initial disruption started on Thursday morning and persisted for about six and a half hours. Thankfully, enough validators were able to implement an emergency patch, which ultimately restored the network.

The initial emergency fix didn’t fully solve the problem. The team knew it carried a small risk of causing the same crash again, particularly if a transaction had several reasons for failing and one of them hid the actual cause. They decided the quick restoration of the network was worth that risk while they worked on a lasting solution. Unfortunately, that exact situation happened on Friday morning, causing the network to go down again. This second outage lasted about three and a half hours.

The Third Problem Was Different

The main team had a solid solution prepared by Friday morning. After validators restarted to implement it, the network was restored. However, no one predicted that this restart process would unexpectedly cause a completely new problem to emerge later that afternoon.

Sui’s system relies on a process that creates randomness for transactions at the beginning of each period. This process needs a certain number of validators to be active to function. Recently, when validators restarted to implement an update, their participation briefly fell below the required level. As a result, the randomness system paused automatically – which was the intended behavior.

The problem occurred after the initial issue was addressed. The system never saved the information that randomness had been disabled. When the validators restarted, they didn’t know randomness was off and kept trying to use it. This caused transactions needing randomness to build up in a queue, waiting for a system that wasn’t working. The process that normally clears this queue before ending an epoch got stuck and couldn’t finish, resulting in an outage that lasted almost six hours.

How It Was Fixed and What Changes

The recent update resolved two issues: a problem with how gas fees were calculated and an issue with maintaining the system’s random number generator. A new feature lets validators jointly end a problematic period of operation if needed, and it was successfully used to resolve the recent issue and return the system to normal. The Foundation has confirmed that user funds were always safe and no transactions were reversed.

After reviewing the incident, we found that AI tools helped speed up finding the problem by giving engineers access to important logs and data. This also meant more engineers could help fix the live network.

The team has pinpointed three key areas that need more work: improving how the system handles disruptions, enhancing the quality of the code that manages transaction fees, and making sure failures are contained so a problem with one transaction doesn’t crash the whole network. They’ve acknowledged that the code for transaction fees has become complicated, making it hard to catch all potential issues through standard code checks. They plan to strengthen these protective systems before the next network upgrade.

How the price reacted

Even though the network was down for about 16 hours over two days, the price of SUI continued to fall even after service was restored. SUI’s price dropped 7.27% on May 28th, when the initial outage started, and selling pressure persisted throughout the weekend. Currently, the price is at $0.876, having fallen below two key support levels.

SUI has fallen to a technically weak position after breaking through several key support levels. The price dropped below the 0.786 Fibonacci level at $0.927, the 100-day Simple Moving Average at $0.965, and an upward-trending support line that had been in place since March. The loss of these three supports suggests further declines are possible.

The chart also highlights the 1.0 Fibonacci level at $0.795, a price SUI hasn’t reached since early February. Above that, the 50-day Simple Moving Average (SMA) at $1.003 and the 100-day SMA at $0.965 are acting as resistance. The Relative Strength Index (RSI) is at 34.51, nearing oversold conditions similar to those seen in February, which might cause the price to stop falling so quickly.

This article is just for informational purposes and shouldn’t be taken as financial, investment, or trading advice. Coindoo.com doesn’t suggest or support any particular investment or cryptocurrency. Before you make any investment decisions, be sure to do your own research and talk to a qualified financial advisor.

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2026-06-01 11:45