On Saturday 16 May 2026 at 18:20 UTC, a SYN flood targeted a tax authority portal customer in Central Europe. The attack peaked at 73.5 Gbps and lasted 114 minutes. Traffic originated from 3721 autonomous systems in 102 countries, predominantly compromised cloud VMs.
| Vector | SYN flood |
| Peak | 73.5 Gbps |
| Duration | 114 min |
| Time to mitigation | 0.221 s |
| Attack traffic reaching origin | 0.012% |
| Legitimate traffic challenged | 0.32% |
Timeline
The attack was preceded by a breaking political story. Edge packet filters identified the flood by source port and payload signature and dropped it at line rate across 19 points of presence.
What the customer saw
A brief increase in p99 latency of 144 ms during the first minute, then normal service.
Recommendations
- Keep origin IPs out of public DNS history.
- Enable authenticated origin pulls.
- Review allow-listed partner ranges quarterly.
Great write-up. We saw almost the same pattern on our login endpoint last month.
Machine-readable ranges are at /ips.json and via the API.
Do you publish the edge IP ranges in a machine-readable format?
Great write-up. We saw almost the same pattern on our login endpoint last month.
Clear and practical, thanks.
Could you share the dataset behind the percentages?
Carpet bombing is nasty. Good to see a clear explanation of it.
Great write-up. We saw almost the same pattern on our login endpoint last month.
Verified good bots and allow-listed partners bypass challenges entirely.
Is the risk score exposed in the logs so we can build our own dashboards on it?
Nice to read a vendor blog that admits what went wrong.
Great to hear, thanks for sharing your experience.