The Astro Technology Company, creators of the Astro web framework, is joining Cloudflare. Astro is the web framework for building fast, content-driven websites. Over the past few years, we’ve seen an incredibly diverse range of developers and companies use Astro to build for the web. This ranges from established brands like Porsche and IKEA, to […]
Tag Archives: security
How to Protect Your Site From Content Sniffing with HTTP Security Headers
Ever had a perfectly “safe” page or file turn into an attack vector out of nowhere? That can happen when browsers start guessing what your content is instead of listening to your server. Browsers sometimes try to figure out what kind of file they’re dealing with if the server doesn’t provide the Content-Type header or […]
The 2025 Cloudflare Radar Year in Review: The rise of AI, post-quantum, and record-breaking DDoS attacks
The 2025 Cloudflare Radar Year in Review is here: our sixth annual review of the Internet trends and patterns we observed throughout the year, based on Cloudflare’s expansive network view. Our view is unique, due to Cloudflare’s global network, which has a presence in 330 cities in over 125 countries/regions, handling over 81 million HTTP […]
How Workers VPC Services connects to your regional private networks from anywhere in the world
In April, we shared our vision for a global virtual private cloud on Cloudflare, a way to unlock your applications from regionally constrained clouds and on-premise networks, enabling you to build truly cross-cloud applications. Today, we’re announcing the first milestone of our Workers VPC initiative: VPC Services. VPC Services allow you to connect to your […]
One IP address, many users: detecting CGNAT to reduce collateral effects
IP addresses have historically been treated as stable identifiers for non-routing purposes such as for geolocation and security operations. Many operational and security mechanisms, such as blocklists, rate-limiting, and anomaly detection, rely on the assumption that a single IP address represents a cohesive, accountable entity or even, possibly, a specific user or device. But the […]
Defending QUIC from acknowledgement-based DDoS attacks
On April 10th, 2025 12:10 UTC, a security researcher notified Cloudflare of two vulnerabilities (CVE-2025-4820 and CVE-2025-4821) related to QUIC packet acknowledgement (ACK) handling, through our Public Bug Bounty program. These were DDoS vulnerabilities in the quiche library, and Cloudflare services that use it. quiche is Cloudflare’s open-source implementation of QUIC protocol, which is the […]
Keeping the Internet fast and secure: introducing Merkle Tree Certificates
The world is in a race to build its first quantum computer capable of solving practical problems not feasible on even the largest conventional supercomputers. While the quantum computing paradigm promises many benefits, it also threatens the security of the Internet by breaking much of the cryptography we have come to rely on. To mitigate […]
Contact Form Spam Attack: An Innocent Feature Caused a Massive Problem
How a simple “Send a copy to yourself” feature led to 149,700 spam emails and what you can do to prevent it The Emergency Call It started like many server emergencies do – with a panicked message about massive server performance issues. A client’s website was grinding to a halt, CPU usage was through the […]
Improving the trustworthiness of Javascript on the Web
The web is the most powerful application platform in existence. As long as you have the right API, you can safely run anything you want in a browser. Well… anything but cryptography. It is as true today as it was in 2011 that Javascript cryptography is Considered Harmful. The main problem is code distribution. Consider […]
Introducing Sucuri Academy: Your New Destination for Website Security Education
Learn. Secure. Lead. We’re excited to introduce the beta launch of Sucuri Academy—a cutting-edge learning platform designed to empower website owners, developers, and digital professionals with the skills to defend against cyber threats. Whether you’re just starting out or looking to master advanced security techniques, Sucuri Academy offers structured, expert-led courses to help you protect […]
