If your website suddenly crawls to a halt, pages time out, or customers report they can’t log in, you might be staring down a Denial-of-Service (DoS) attack. These incidents don’t require exotic zero-days or deep levels of access. More often, they’re brutally simple: overwhelm the target with traffic or requests until legitimate users can’t get […]
Tag Archives: ddos
MadeYouReset: An HTTP/2 vulnerability thwarted by Rapid Reset mitigations
On August 13, security researchers at Tel Aviv University disclosed a new HTTP/2 denial-of-service (DoS) vulnerability that they are calling MadeYouReset (CVE-2025-8671). This vulnerability exists in a limited number of unpatched HTTP/2 server implementations that do not sufficiently enforce restrictions on the number of times a client may send malformed frames. If you’re using Cloudflare […]
Hyper-volumetric DDoS attacks skyrocket: Cloudflare’s 2025 Q2 DDoS threat report
Welcome to the 22nd edition of the Cloudflare DDoS Threat Report. Published quarterly, 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 second quarter of 2025. To view previous reports, visit www.ddosreport.com. […]
Defending the Internet: how Cloudflare blocked a monumental 7.3 Tbps DDoS attack
In mid-May 2025, Cloudflare blocked the largest DDoS attack ever recorded: a staggering 7.3 terabits per second (Tbps). This comes shortly after the publication of our DDoS threat report for 2025 Q1 on April 27, 2025, where we highlighted attacks reaching 6.5 Tbps and 4.8 billion packets per second (pps). The 7.3 Tbps attack is […]
Targeted by 20.5 million DDoS attacks, up 358% year-over-year: Cloudflare’s 2025 Q1 DDoS Threat Report
Welcome to the 21st edition of the Cloudflare DDoS Threat Report. Published quarterly, 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 first quarter of 2025. To view previous reports, visit www.ddosreport.com. […]
Extending Cloudflare Radar’s security insights with new DDoS, leaked credentials, and bots datasets
Security and attacks continues to be a very active environment, and the visibility that Cloudflare Radar provides on this dynamic landscape has evolved and expanded over time. To that end, during 2023’s Security Week, we launched our URL Scanner, which enables users to safely scan any URL to determine if it is safe to view […]
QUIC action: patching a broadcast address amplification vulnerability
Cloudflare was recently contacted by a group of anonymous security researchers who discovered a broadcast amplification vulnerability through their QUIC Internet measurement research. Our team collaborated with these researchers through our Public Bug Bounty program, and worked to fully patch a dangerous vulnerability that affected our infrastructure. Since being notified about the vulnerability, we’ve implemented […]
Cloudflare thwarts over 47 million cyberthreats against Jewish and Holocaust educational websites
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 to the Nazi regime’s campaign of hatred and intolerance. This tragic chapter in human history serves as a stark reminder of the […]
Record-breaking 5.6 Tbps DDoS attack and global DDoS trends for 2024 Q4
Welcome to the 20th edition of the Cloudflare DDoS Threat Report, marking five years since our first report in 2020. Published quarterly, 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 fourth […]
Global elections in 2024: Internet traffic and cyber threat trends
Elections define the course of democracies (even as there are several types of democracies), and 2024 was a landmark year, with over 60 countries — plus the European Union — holding national elections, impacting half the world’s population. As highlighted in Pew Research’s global elections report, this was a year of “political disruption,” where the […]
