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[Incident Report] Base sequencer attack May 17 23:29 UTC — P99 leading indicator preceded revert spike by 27s #643

Description

@kant19801201behax5

Summary

On May 17, 2026 at 23:29:43 UTC we recorded a structured two-wave MEV attack on Base. Our sequencer RTT probe (2-second intervals, DO NYC1) detected the attack 27 seconds before the revert ratio spiked.

Timeline — second-by-second data

Wave 1:

Time UTC Base P99 Revert Ratio
23:29:40 52ms ~2% (normal)
23:29:43 739ms ~2%
23:30:10 791ms 56%
23:31:10 1130ms 56%
23:31:12 59ms 56%

Between waves (23:33–23:36):

  • P99 remains 200–248ms (elevated baseline, not normal)
  • Revert ratio 11–17%

Wave 2 + Full Stall:

Time UTC Base P99 Revert Ratio
23:39:35 64ms 61.36%
23:41:17 398ms ~28%
23:41:52 5000ms
23:42:38 121ms
23:42:47 5000ms

Total duration: ~13 minutes of degraded conditions.

Key Finding

P99 RTT is a 27-second leading indicator for revert ratio spikes.

Standard RPC endpoints report state after block processing. A continuous low-latency probe to the sequencer detects mempool pressure building at the ingress layer — before it manifests as transaction failures.

Why this matters for Moonwell

During the 23:30–23:42 window, any liquidation or supply transaction submitted without awareness of sequencer state was executing into a degraded network. The P99 signal gives a ~27 second window to pause liquidation bots or adjust gas strategy.

Data source

Phoenix Zero RTT Oracle — continuous 2s probes to Base, Arbitrum, Optimism, ZKSync from DO NYC1.

Public feed (5-min delayed, free): https://rtt.phoenix-ai.work/api/public-feed
Dashboard: https://phoenix-zero.vercel.app

If your DevOps or keeper team wants real-time access (0ms delay) as a pre-flight signal: aleksandrkent64@gmail.com

Activity

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