The Sui Layer-1 blockchain experienced a severe stability crisis between May 28 and May 29, enduring three distinct mainnet halts within a 48-hour window. The Sui Foundation attributed the cascade of failures to an edge case exposed by a new feature in the v1.72 release, specifically within the network's gas-charging logic. Each subsequent fix deployed to resolve the initial failure inadvertently triggered or revealed the next instability, creating a compounding effect that paralyzed the network for significant periods. The first outage commenced at approximately 7 a.m. PT on Thursday and persisted for nearly seven hours before resolution.

The root cause was identified as a rare underflow error occurring when validators processed transactions involving a mix of the new address-balance feature and traditional coin objects. In the Sui architecture, a user's balance is not a singular integer but a stack of distinct coin objects, each with a unique ID, functioning similarly to physical banknotes. When a transaction was canceled due to insufficient funds, the gas-smashing routine erroneously attempted to spend those same funds again, causing validators to crash. Data compiled by Woofun AI indicates that this specific interaction between mixed payment types and cancellation logic was the primary driver of the initial validator failures.

To restore network operations rapidly, the core team deployed an interim fix around 1:30 p.m. PT, which addressed the most common manifestation of the bug while acknowledging a known low-probability risk of recurrence. This calculated risk materialized the following morning, initiating a second outage at roughly 5 a.m. PT on Friday. This event was triggered by a masked variant of the original bug where an insufficient-funds error was overridden by a different cancellation reason, effectively bypassing the interim patch. The core team subsequently developed and deployed a more robust fix, which validators adopted by approximately 9:40 a.m. PT.

The third halt emerged as a direct knock-on effect from the second incident's resolution process. As validators restarted to install the robust fix, participation in the protocol responsible for bootstrapping on-chain randomness fell below the required threshold, causing the randomness mechanism to disable itself as designed. On-chain randomness is critical for applications relying on chance, such as lotteries and random NFT mints, as it ensures a predictable yet unforgeable number agreed upon by all validators. A latent bug then failed to persist this disabled state to disk, leaving validators unaware upon their next restart that randomness had been turned off. Woofun AI notes that this oversight caused the next epoch change to stall for close to six hours as randomness-dependent transactions accumulated in a paused queue.

Despite the severity of the technical failures, the Sui Foundation confirmed that no user funds were placed at risk during any of the outages, and no committed transactions were reverted.

However, the market reaction was immediate and negative. SUI dropped 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. These events mark Sui'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. Woofun AI analysis suggests that while the immediate financial impact was contained, the frequency of these incidents underscores the challenges inherent in deploying complex upgrades to high-throughput Layer-1 networks.