DDoS

Cloudflare’s global network has officially crossed 500 Tbps of external capacity, enough to route more than 20% of the web and absorb the largest DDoS attacks ever recorded.

Tanner Ryan

Magic Transit customers can now program their own DDoS mitigation logic and deploy it across Cloudflare’s global network. This enables precise, stateful mitigation for custom and proprietary UDP protocols.

Anita Tenjarla, Alex Forster, Cody Doucette, and Venus Xeon-Blonde

The number of DDoS attacks more than doubled in 2025. The network layer is under particular threat as hyper-volumetric attacks grew 700%.

Omer Yoachimik, Jorge Pacheco, and Cloudforce One

Welcome to the 23rd edition of Cloudflare’s Quarterly DDoS Threat Report. This report offers a comprehensive analysis of the evolving threat landscape of Distributed Denial of Service (DDoS) attacks based on data from the Cloudflare network. In this edition, we focus on the third quarter of 2025.

Omer Yoachimik and Jorge Pacheco

HTTP/2 implementations often respond to suspected attacks by closing the connection with an ENHANCE_YOUR_CALM error code. Learn how a common pattern of using Go's HTTP/2 client can lead to unintended errors and the solution to avoiding them.

Lucas Pardue and Zak Cutner

Fogos.pt, a volunteer-run wildfire tracker in Portugal, grew from a side project into a critical national resource used by citizens, media, and government. During 2025 fire season it was hit by DDoS

João Tomé

A new HTTP/2 denial-of-service (DoS) vulnerability called MadeYouReset was recently disclosed by security researchers. Cloudflare HTTP DDoS mitigation, already protects from MadeYouReset.

Alex Forster, Noah Maxwell Kennedy, Lucas Pardue, and Evan Rittenhouse

June was the busiest month for DDoS attacks in 2025 Q2, accounting for nearly 38% of all observed activity.

Omer Yoachimik and Jorge Pacheco

In mid-May 2025, Cloudflare blocked the largest DDoS attack ever recorded: a staggering 7.3 terabits per second (Tbps).

Omer Yoachimik

DDoS attacks are surging. In 2025 Q1, Cloudflare blocked +20M attacks (a 358% YoY spike) along with 5.6 Tbps and 4.8 Bpps record-breaking attacks.

Omer Yoachimik and Jorge Pacheco

For Security Week 2025, we are adding several new DDoS-focused graphs, new insights into leaked credential trends, and a new Bots page to Cloudflare Radar.

David Belson

Cloudflare was recently contacted by researchers who discovered a broadcast amplification vulnerability through their QUIC Internet measurement research. We've implemented a mitigation.

Josephine Chow, June Slater, Bryton Herdes, and Lucas Pardue

January 27 marks the International Holocaust Remembrance Day — a solemn occasion to honor the memory of the six million Jews who perished in the Holocaust, along with countless others who fell victim

Omer Yoachimik

2024 ended with a bang. Cloudflare mitigated another record-breaking DDoS attack peaking at 5.6 Tbps.

Omer Yoachimik and Jorge Pacheco

In 2024, as elections took place across over 60 countries, the Internet became both a battleground for cyberattacks and a vital platform for democratic engagement.

João Tomé

How significant are Cyber Week shopping days on the Internet? Is it a global phenomenon? Does E-commerce interest peak on Black Friday or Cyber Monday, and are attacks increasing during this time?

João Tomé

If we plot the metrics associated with large DDoS attacks observed in the last 10 years, does it show a straight, steady increase in an exponential curve that keeps becoming steeper, or is it closer to a linear growth? Our analysis found the growth is not linear but rather is exponential, with the slope varying depending on the metric (rps, pps or bps).

José Salvador

Election Day 2024 in the US saw a surge in cyber activity. Cloudflare blocked several DDoS attacks on political and election sites, ensuring no impact. In this post, we analyze these attacks, as well

João Tomé and Jocelyn Woolbright