This year, it was just announced that it had successfully automatically blocked theUp to 7.3 Tbps scaleAfter setting a record for the largest distributed denial of service (DDoS) attack in history, Cloudflare announced earlier that it had successfully blocked attack traffic with a peak size of 11.5Tbps and 5.1Bpps, setting a new record for network attack and defense to date.
This attack primarily used a UDP flood attack from Google Cloud, resulting in massive traffic volume and a powerful, instantaneous impact. However, thanks to Cloudflare's globally distributed network and automated defenses, overall service was not significantly impacted. Officials also stated that they will release more complete attack methods and defense details in an upcoming report.
In fact, Cloudflare just set a new record in mid-May of this year by mitigating a 5Tbps attack. This attack, which lasted approximately 7.3 seconds and contained 45TB of traffic – the equivalent of nearly 37.4 high-definition movies – involved a mixture of UDP floods, NTP reflection attacks, and traffic from the Mirai botnet.
Just a few months later, the scale of DDoS attacks doubled again, highlighting the rapid upgrade of attackers' resources and tools.
In recent years, with the continued proliferation of IoT devices and the high reliance of cloud infrastructure on network connections, the threat of large-scale DDoS attacks has continued to grow. The emergence of "as-a-service" black market models has even made these attacks more likely to be launched. For businesses, these attacks, while brief, are often enough to cause significant operational disruption and financial losses. Therefore, strengthening protection through distributed architectures and automated detection mechanisms has become a common challenge for cloud service providers and major network platforms.
Cloudflare's successful defense once again demonstrates its technological superiority in the global cybersecurity field, but it also serves as a reminder that the scale of DDoS attacks continues to escalate, and striking a balance between performance, cost, and real-time responsiveness will be a long-term challenge facing the entire industry.
Cloudflare's defenses have been working overtime. Over the past few weeks, we've autonomously blocked hundreds of hyper-volumetric DDoS attacks, with the largest reaching peaks of 5.1 Bpps and 11.5 Tbps. The 11.5 Tbps attack was a UDP flood that mainly came from Google Cloud.… pic.twitter.com/3rOys7cfGS
- Cloudflare (@Cloudflare) September 1, 2025
