On Saturday 18 April 2026 at 02:14 UTC, a Slowloris targeted a video streaming customer in the Benelux. The attack peaked at 727.5 million requests per second and lasted 28 minutes. Traffic originated from 1670 autonomous systems in 65 countries, predominantly hijacked home routers.
| Vector | Slowloris |
| Peak | 727.5 million requests per second |
| Duration | 28 min |
| Time to mitigation | 0.711 s |
| Attack traffic reaching origin | 0.037% |
| Legitimate traffic challenged | 0.54% |
Timeline
The attack was preceded by a breaking political story. Request rates on the targeted routes exceeded their hourly baseline by a factor of 546 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
The customer’s status page stayed green throughout; they learned about the attack from our notification.
Recommendations
- Enable authenticated origin pulls.
- Lower challenge thresholds on authentication endpoints during high-risk events.
- Review allow-listed partner ranges quarterly.
Is the risk score exposed in the logs so we can build our own dashboards on it?
Thanks! Yes — the risk score and its components are included in every log record.
We had the exact false-positive issue with CGNAT carriers. The weighting change makes sense.
Machine-readable ranges are at /ips.json and via the API.
How do you avoid challenging uptime monitors and partners?
Verified good bots and allow-listed partners bypass challenges entirely.
How do you avoid challenging uptime monitors and partners?
How do you avoid challenging uptime monitors and partners?
Great to hear, thanks for sharing your experience.
Our auditors asked for exactly this kind of incident evidence under DORA.