On November 22, Sui released an analysis report on yesterday's downtime, saying that the Sui mainnet was completely down from 5:15 to 7:45 pm on November 21 due to a congestion control code vulnerability. All verification nodes fell into a crash loop and transaction processing stopped. The problem originated from the "TotalGasBudgetWithCap" mode enabled in protocol v68, which triggered a crash when a special transaction containing "mutable shared object input" and "zero MoveCall instructions" was received. The Sui team quickly diagnosed the problem and released a fixed version v1.37.4. The verifier completed the deployment within 15 minutes and restored the normal operation of the network. Sui plans to reduce similar problems and response times by improving the test system and optimizing the build process.