On Wednesday 9 July 2025 at 21:27 UTC, a HTTP/2 rapid reset targeted a ticketing customer in Central Europe. The attack peaked at 147.5 million requests per second and lasted 130 minutes. Traffic originated from 1755 autonomous systems in 40 countries, predominantly a headless-browser farm.
| Vector | HTTP/2 rapid reset |
| Peak | 147.5 million requests per second |
| Duration | 130 min |
| Time to mitigation | 0.670 s |
| Attack traffic reaching origin | 0.041% |
| Legitimate traffic challenged | 0.73% |
Timeline
The attack was preceded by a hacktivist channel announcing the target. Request rates on the targeted routes exceeded their hourly baseline by a factor of 408 within 27 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
No customer-visible impact. The on-call engineer was notified and acknowledged the incident from the dashboard.
Recommendations
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Add a dedicated rate limit for the targeted route.
- Enable authenticated origin pulls.