On Saturday 30 May 2026 at 13:38 UTC, a HTTP/2 rapid reset targeted a retail banking customer in Western Europe. The attack peaked at 360.2 million requests per second and lasted 101 minutes. Traffic originated from 3522 autonomous systems in 44 countries, predominantly a headless-browser farm.
| Vector | HTTP/2 rapid reset |
| Peak | 360.2 million requests per second |
| Duration | 101 min |
| Time to mitigation | 0.488 s |
| Attack traffic reaching origin | 0.038% |
| Legitimate traffic challenged | 0.02% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 731 within 37 seconds. The risk score of participating clients crossed the challenge threshold automatically and proof-of-work difficulty rose with origin load.
What the customer saw
A brief increase in p99 latency of 26 ms during the first minute, then normal service.
Recommendations
- Enable log streaming to your SIEM for faster correlation.
- Keep origin IPs out of public DNS history.
- Add a dedicated rate limit for the targeted route.