CoinDesk
Sui's mainnet halted three separate times across May 28 and May 29 after a new address-balance feature shipped in the v1.72 release exposed an edge case in the Layer-1 blockchain's gas-charging logic, the Sui Foundation said in a post-mortem published Sunday. Each fix either triggered or exposed the next failure, with the chain offline for a combined stretch of roughly 18 hours.
The first outage began around 7 a.m. PT on Thursday and lasted close to seven hours. According to the foundation, it stemmed from a rare issue in how the network charged gas for transactions paying with a mix of the new address-balance feature and traditional coin objects. Validators crashed with an underflow error when a transaction was canceled for insufficient funds, but the gas-smashing routine still tried to spend those same funds. The core team brought mainnet back up around 1:30 p.m. PT with an "interim fix" that accepted a known low-probability risk of triggering another halt.
That risk materialized the next morning. A second outage began around 5 a.m. PT on Friday when a masked variant of the same bug bypassed the interim patch, and the team finished a more robust fix that validators adopted by about 9:40 a.m. PT. The third halt followed as a knock-on: when validators restarted to install the fix, participation in the protocol that bootstraps on-chain randomness fell below the required threshold and randomness disabled itself as designed — and a latent bug then failed to persist that disabled state to disk, stalling the next epoch change for close to six hours.
Why it matters
Three halts in 48 hours is the kind of pattern institutional allocators and bridge operators treat as a structural risk flag, even when no funds are at risk. The cascade is the harder sell than any single outage — each interim fix carried a known risk the team accepted, and that risk landed the next morning. Sui's pitch as a high-throughput, consumer-grade Layer-1 lives or dies on uptime, and this is now the network's third major reliability incident since its 2023 mainnet launch, following a two-hour transaction-scheduling bug in November 2024 and a six-hour consensus divergence in January 2026.
Frequently asked questions
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What caused the three Sui mainnet outages on May 28 and 29?
A new address-balance feature shipped in the v1.72 release exposed an edge case in Sui's gas-charging logic. The first two halts came from bugs in mixed gas payments when transactions lacked sufficient funds; the third was a knock-on failure in the on-chain randomness protocol triggered by the validator restart that…
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Were any user funds lost or transactions reversed during the outages?
No. The Sui Foundation's post-mortem states no user funds were at risk during any of the three halts and no committed transactions were reverted.
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How much did the SUI token drop during the outage cascade?
$SUI fell roughly 8% during the cascade to a low of $0.90 and was trading near $0.90 on Monday, leaving the token down about 19% on the week, per CoinDesk data.
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How many major reliability incidents has Sui had since mainnet launch?
Three: the May 28–29 cascade, a two-hour transaction-scheduling bug in November 2024, and a six-hour consensus divergence in January 2026. Sui mainnet launched in 2023.
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What is the on-chain randomness bug that caused the third outage?
When validators restarted to install the second fix, participation in the randomness-bootstrap protocol fell below the required threshold and randomness disabled itself as designed. A latent bug then failed to persist that disabled state to disk, so validators on the next restart were unaware randomness was off and…
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