Cloudflare Thwarts Record-Shattering 11.5 Tbps DDoS Attack

Cloudflare has announced the successful mitigation of a colossal Distributed Denial of Service (DDoS) attack, reaching an unprecedented peak of 11.5 terabits per second (Tbps). This massive volumetric attack, primarily a UDP flood, lasted approximately 35 seconds and targeted an unnamed entity, highlighting the escalating scale of cyber threats.

Key Takeaways

• Cloudflare blocked a record-breaking DDoS attack peaking at 11.5 Tbps.

• The attack was a UDP flood that lasted about 35 seconds.

• Initial reports indicated Google Cloud as a primary source, later clarified to be a combination of IoT and cloud providers.

• This incident follows a previous record of 7.3 Tbps mitigated by Cloudflare just two months prior.

The Scale of the Attack

The sheer volume of data directed at the target underscores the growing sophistication and power of DDoS attacks. Volumetric attacks like this aim to overwhelm a system's resources with a flood of traffic, leading to service degradation or complete outages. The attack also involved an immense packet rate, reaching 5.1 billion packets per second (Bpps), further straining network infrastructure.

Attribution and Evolution of Threats

Initially, Cloudflare reported that the attack predominantly originated from Google Cloud infrastructure. However, a subsequent clarification indicated that the traffic stemmed from a broader mix of Internet of Things (IoT) devices and various cloud providers, with Google Cloud being only one component. This shift in attribution highlights the distributed and complex nature of modern botnets used in such assaults.

A Trend of Escalating Attacks

This latest record-breaking event follows closely on the heels of another massive attack mitigated by Cloudflare in May 2025, which peaked at 7.3 Tbps. These incidents demonstrate a clear upward trend in the size and frequency of hyper-volumetric DDoS attacks. In the first half of 2025 alone, Cloudflare reported mitigating 27.8 million DDoS attacks, surpassing the total for the entirety of 2024. The increasing prevalence of IoT devices, often with inherent security vulnerabilities, provides a fertile ground for attackers to build powerful botnets capable of launching these devastating assaults.

As cyber threats become increasingly sophisticated, your security strategy must evolve to keep pace. BetterWorld Technology offers adaptive cybersecurity solutions that grow with the threat landscape, helping your business stay secure while continuing to innovate. Reach out today to schedule your personalized consultation.

Sources

• Cloudflare Blocks Record-Breaking 11.5 Tbps DDoS Attack, The Hacker News.

• Cloudflare Blocks Record-Breaking 11.5 Tbps DDoS Attack, SecurityWeek.

• Cloudflare blocks record-setting 11.5Tbps DDoS attack two months after the previous record-setting DDoSattack, Tom's Hardware.

• Cloudflare blocks largest recorded DDoS attack peaking at 11.5 Tbps, BleepingComputer.

• Cloudflare blocks another largest recorded DDoS attack - this time, peaking at 11.5 Tbps, TechRadar.