On Friday 26 June 2026 at 15:33 UTC, a TLS handshake exhaustion targeted a news publisher customer in the UK. The attack peaked at 545.0 million requests per second and lasted 120 minutes. Traffic originated from 1759 autonomous systems in 81 countries, predominantly a rented booter service.
| Vector | TLS handshake exhaustion |
| Peak | 545.0 million requests per second |
| Duration | 120 min |
| Time to mitigation | 0.770 s |
| Attack traffic reaching origin | 0.074% |
| Legitimate traffic challenged | 0.07% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 588 within 22 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
- Enable log streaming to your SIEM for faster correlation.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Add a dedicated rate limit for the targeted route.
Any plans to support per-tenant limits keyed on a JWT claim?
Interesting that most attacks are under ten minutes. Our experience is similar.
Our auditors asked for exactly this kind of incident evidence under DORA.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Great to hear, thanks for sharing your experience.
Clear and practical, thanks.
Verified good bots and allow-listed partners bypass challenges entirely.
Any plans to support per-tenant limits keyed on a JWT claim?