Attacks

August 19, 2026

A revisit of remote Spectre attacks on Cloudflare Workers

In 2024 and 2025, we reassessed remote Spectre attacks on our Workers infrastructure. We share details about the new attack primitives like Spectre gadgets, remote timers, achieving co-location and how new defenses further harden Cloudflare Workers.

August 11, 2026

Cloudflare DDoS Threat Report H1 2026: 1 Tbps attacks soar as DNS floods and geopolitical tensions drive a new wave

In the first half of 2026, Cloudflare detected a 519% surge in hyper-volumetric DDos attacks across its network. These attacks were driven heavily by DNS and CLDAP reflection vectors. This report breaks down how major geopolitical conflicts reshaped the global cyber threat landscape.

September 25, 2025

Safe in the sandbox: security hardening for Cloudflare Workers

We are further hardening Cloudflare Workers with the latest software and hardware features. We use defense-in-depth, including V8 sandboxes and the CPU's memory protection keys to keep your data safe.

August 14, 2025

MadeYouReset: An HTTP/2 vulnerability thwarted by Rapid Reset mitigations

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.

April 27, 2025

Targeted by 20.5 million DDoS attacks, up 358% year-over-year: Cloudflares 2025 Q1 DDoS Threat Report

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.

January 27, 2025

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

January 21, 2025

Record-breaking 5.6 Tbps DDoS attack and global DDoS trends for 2024 Q4

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

November 20, 2024

Bigger and badder: how DDoS attack sizes have evolved over the last decade

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).

October 23, 2024

4.2 Tbps of bad packets and a whole lot more: Cloudflare's Q3 DDoS report

The number of DDoS attacks spiked in the third quarter of 2024. Cloudflare mitigated nearly 6 million DDoS attacks, representing a 49% increase QoQ and 55% increase YoY.

October 2, 2024

How Cloudflare auto-mitigated world record 3.8 Tbps DDoS attack

Over the past couple of weeks, Cloudflare's DDoS protection systems have automatically and successfully mitigated multiple hyper-volumetric L3/4 DDoS attacks exceeding 3 billion packets per second (Bpps). Our systems also automatically mitigated multiple attacks exceeding 3 terabits per second (Tbps), with the largest ones exceeding 3.65 Tbps. The scale of these attacks is unprecedented.

September 27, 2024

Network trends and natural language: Cloudflare Radars new Data Explorer & AI Assistant

The Cloudflare Radar Data Explorer provides a simple Web-based interface to build more complex API queries, including comparisons and filters, and visualize the results. The accompanying AI Assistant translates a users natural language statements or questions into the appropriate Radar API calls.

July 9, 2024

DDoS threat report for 2024 Q2

Welcome to the 18th edition of the Cloudflare DDoS Threat Report. Released quarterly, these reports provide an in-depth analysis of the DDoS threat landscape as observed across the Cloudflare network. This edition focuses on the second quarter of 2024

July 8, 2024

French elections: political cyber attacks and Internet traffic shifts

Check the dynamics of the 2024 French legislative elections, the surprising election results impact on Internet traffic changes, and the cyber attacks targeting political parties

June 26, 2024

Automatically replacing polyfill.io links with Cloudflares mirror for a safer Internet

polyfill.io, a popular JavaScript library service, can no longer be trusted and should be removed from websites

June 6, 2024

Dutch political websites hit by cyber attacks as EU voting starts

The 2024 European Parliament election began in the Netherlands on June 6. Cloudflare mitigated several multi-hour DDoS attacks on Dutch political websites on June 5 and 6

April 16, 2024

DDoS threat report for 2024 Q1

2024 started with a bang. Cloudflares autonomous systems mitigated over 4.5 million DDoS attacks in the first quarter of the year a 50% increase compared to the previous year. Read the full coverage

March 6, 2024

Eliminate VPN vulnerabilities with Cloudflare One

The Cybersecurity & Infrastructure Security Agency (CISA) recently issued an Emergency Directive due to the Ivanti Connect Secure and Policy Secure vulnerabilities. In this blog, we discuss the threat actor tactics exploiting these vulnerabilities

January 9, 2024

DDoS threat report for 2023 Q4

Welcome to the sixteenth edition of Cloudflares DDoS Threat Report. This edition covers DDoS trends and key findings for the fourth and final quarter of the year 2023, complete with a review of major trends throughout the year