Today, we are expanding our web application firewall (WAF) by adding two new capabilities: full transaction detections and response rules. Full transaction detections evaluate each HTTP request alongside its response to identify evidence of exploitation. It helps answer both "Does this request look malicious?" and "What happened when the application handled it?" Response rules can then block the origin’s response before it reaches the requester.
These are valuable protections because the latest frontier models are uncovering vulnerabilities buried deep in widely used software, giving defenders clarity on what to fix — and attackers new paths to exploit. The recent php2shell vulnerability shows the stakes: a flaw in a common software component can put applications across the Internet at risk. AI agents scanning for vulnerabilities can be extremely persistent, adapting payloads using feedback, and chaining vulnerabilities, credentials, and permissions. An application's response can reveal whether an attempt worked and give an attacker information that helps them go deeper.
Inspecting incoming requests remains essential for stopping recognizable attacks before they reach an application. But some threats become clear only when the request is considered alongside what the origin returns. A suspicious input followed by a response exposing sensitive information tells Continue reading
Today, Calif.io, Wiz, OpenAI and Quarkslab disclosed two vulnerabilities in PHP, tracked as CVE-2026-109618 and CVE-2026-109619 and known as php2shell. The vulnerabilities affect all web servers running PHP 5.4 or later and they may allow an attacker to cause denial of service, remote code execution, and data exposure when an application processes specially crafted HTTP traffic.
Cloudflare has been part of a coordinated effort to deploy mitigations to protect the Internet, working with PHP foundation, OpenAI and Wiz among others. Cloudflare has developed and deployed web application firewall (WAF) protections since early October 2026, which were deployed about 9 hours ahead of public disclosure. Starting on October 21 3:02 am UTC, Cloudflare customers using our free or paid WAF were protected by default against php2shell.
Cloudflare successfully deployed multiple mitigations for all its customers while the vulnerability was leaked before the official release date and we observed attack traffic targeting our customers. We observed how attackers were mutating the attack payload to try to bypass our protections by tracking the volume of matches and cross-referencing with the rule logic.
Protecting against php2shell required more than standard request-based rules. Request data alone does not always provide enough evidence to distinguish an Continue reading
On October 19, 2026, at approximately 17:00 UTC, Cloudflare became aware that private keys associated with eight eMudhra intermediate certificates were compromised. These certificates were widely trusted by browsers, operating systems, and also within Cloudflare. Because the keys themselves are weak, an attacker can create a forged certificate for any domain and use it to impersonate servers to intercept or modify traffic. This is a serious security incident with implications across the Internet. For reference, here is a link to more information about how SSL certificates work and why they are so critical to the operation of the Internet.
We immediately prioritized patching critical services across Cloudflare to protect our customers ahead of the public disclosure of the vulnerability. Our security review has not identified active exploitation of this issue on Cloudflare services.
We have released updates for the Cloudflare One Clients, also known as WARP or the 1.1.1.1 app, and Cloudflare Tunnel, also known as cloudflared. We have also deployed mitigations across our CDN, Developer, and Zero Trust products. If you are using Cloudflare Zero Trust with Gateway and an up-to-date client (see below), you are automatically protected.
We prioritized updating services that use public certificates Continue reading
The recent disclosure of a major vulnerability in Citrix NetScaler pointed to a widespread weak point: a login page is an attack surface that can be used to compromise and access an application server. Indeed, the disclosures included an actively exploited flaw that allowed attackers to execute commands on affected gateways without signing in. As with any emergency patch, admins had to weigh cutting off or disrupting their users’ access with the risk of delaying a critical security update.
If you’re a NetScaler customer and you haven’t patched your instance, stop reading and go do that. This was a bad one. Once you’ve finished the patch, we’ll explore how to avoid a future fire drill by laying additional security controls.
This issue extends beyond NetScaler and can be applied to any internal application available on the Internet. Remote desktop portals, administrative consoles, and other publicly accessible authentication pages all deserve the same scrutiny: Does the intended audience require unrestricted Internet reachability? And can an attacker bypass this authentication check to reach the application's server?
Citrix released software updates to address the flaw, and Cloudflare followed with an emergency web application firewall (WAF) rule on October 1. But having a patch available Continue reading
A driver’s license tells you who someone is and that they passed a driving test, not whether they’ll drive responsibly in the future. The same is true for bots: verifying who operates it creates accountability, but trust depends on what it does next. A known bot can still ignore website preferences, overwhelm origins, or evade controls. It’s not always malicious — often it’s just a misconfiguration or a bug.
As we described in a previous blog post on bot behavior, we strive to verify two questions: “Are you who you say you are?” and “Can we trust you?” To be a Cloudflare Verified Bot, you broadly need to meet three criteria:
Bots use Web Bot Auth to sign requests that establish their identity, which BotBase then catalogues in an open format. With identification addressed, our focus shifts to the second cardinal rule of Verified bots: thou shalt do no harm.
Today we introduce a system to evaluate and report when Verified bot behavior starts to deviate from this rule, ensuring that the answer to “Can we trust you?” remains “Yes.”
Security alerts rarely arrive one at a time. A single alert can cause a spike across the environment, requiring a human analyst to decide which alerts are related and what they mean. When multiple arrive at the same time, it can quickly overwhelm even a seasoned security analyst. Enter the alert paradox. Now, our built-in, multi-AI-agent security operations harness can handle more of this work at Cloudflare scale.
Our Cloudflare Managed Defense AI agent harness speeds up the process of gathering data, connecting and aggregating detections, and accounting for missing sources while new alerts continue to arrive. To further analyze context, we make use of the OpenAI Daybreak Defense Network and our partnership with Anthropic. Cloudflare uses approved OpenAI Daybreak and Anthropic models, including GPT-5.6 Cyber and Mythos, for deeper model-backed analysis. Initial analysis and scoring is done with Clef, Cloudflare’s open-source decision model.
Collecting evidence to understand what each alert means requires a lot of time. Even in a highly sophisticated Security Information and Event Management (SIEM), too much is still left for a human to review. Human analysts must gather data, connect and aggregate detections, and account for missing sources while new alerts continue to arrive.
Think about every Continue reading
We launched Quick Tunnels in 2021 to give developers an easy way to share their latest service, application, or project running in their local development environment. A lot has changed since then, but the core use case remains the same.
Your coding agent has just finished the feature. The dev server is up on localhost:5173, and before you ask, the agent offers to let you try it on your phone. It runs one command and hands you a link:
That command starts a Quick Tunnel. cloudflared, Cloudflare's lightweight connector, publishes your local service at a random trycloudflare.com URL. No account, no domain, no cost. Agents now use Quick Tunnels for the same reason people do: they are the shortest path from a local port to a URL.
The catch has always been the same. Anyone with the link can open it.
Starting with cloudflared 2026.9.3, you can add --allowed-mail to the command, and your Quick Tunnel only lets in the email addresses and domains you choose. Visitors prove they own one of those addresses with a one-time PIN from Cloudflare Access. Nobody, on either side, needs a Cloudflare account.
Traditionally, preventing online fraud relied on point-in-time proof of identity: enter the correct password, complete a biometric verification, or pass a liveness check, and gain access. To defeat these controls, fraudsters had to steal credentials and other identity evidence from a real user, which was difficult to execute and scale. Today, widespread access to AI enables fraudsters to fabricate or imitate legitimate identities by combining exposed credentials with synthetic media designed to evade identity verification. Consequently, identity checks are no longer sufficient as they capture a moment in time. Even when someone passes a check, it does not mean the account itself can be trusted.
One convincing interaction can be faked. A consistent pattern of legitimate behavior is much harder to manufacture. Modern fraud prevention must move beyond stateless decisions toward a stateful trust model. Traditional identity verification asks, “Can this person pass the check right now?” A stateful approach additionally asks, “Does it fit what we know about this account and its established behavior?” At Cloudflare, trust is continually earned and reassessed at each interaction against historical behavioral, network, and device patterns.
Cloudflare’s Account Abuse Protection (AAP) creates stateful account overviews to help website owners detect and investigate abuse across Continue reading
It's Birthday Week, when we traditionally ship presents to the Internet. This year, two of them come from Europe: EuroLLM, which covers all 24 official EU languages, and Apertus, Switzerland's fully open model, trained on more than 1,500 languages. Both were built by public universities and research institutions. Both are coming to Workers AI, and you can request access today.
We're also launching hands-on workshops that help government cyber agencies and critical infrastructure operators build AI defenses that work with any model. The first runs in Singapore in October.
Today's announcements follow from an argument we made a year ago, when questions about AI access and sovereignty were swirling in national capitals. Our answer was choice: the freedom to pick the right tools for the job, and to switch when you need to.
Since then, those conversations have hardened. Attackers have used frontier models to run cyber attacks. Access to some frontier models now depends on where you are. Calls to restrict open models are getting louder. Put it all together and it's easy to conclude that AI sovereignty is zero-sum: every model another country controls is one you can't count on, so the safe move is to build walls.
Twelve years ago, during Birthday Week 2014, we turned on Universal SSL and nearly doubled the number of encrypted sites on the web overnight, giving free TLS to every site behind Cloudflare, including the ones that never paid us a cent. Encryption stopped being an expensive, time-intensive undertaking and instead became the default.
For Birthday Week this year, we are taking the next step on that path. For more than a decade we have been one of the largest consumers of publicly trusted certificates on the Internet, and have never issued a single one ourselves. That is changing. Cloudflare is announcing our intent to become a public certificate authority (CA).
Today we are announcing the first concrete milestones in that effort: We have applied for inclusion in the Chrome, Apple, Microsoft, and Mozilla root programs, and we have signed a definitive agreement to acquire an established, broadly trusted root from GlobalSign, so that we can offer certificates with the widest possible device reach the day we begin issuing. We’re also announcing our plans to be one of the first CAs to serve post-quantum certificates, targeting Chrome’s recently announced Quantum-resistant Root Program.
We are not issuing certificates yet, and it will be Continue reading
As laboratories around the world race to build out a cryptographically relevant quantum computer, we at Cloudflare are racing towards a 2029 target deadline for full post-quantum readiness. While we’ve already transitioned many of our products to post-quantum encryption, we still have work to do to support post-quantum authentication and achieve full post-quantum readiness across our platform.
We’re taking a maximalist stance (“PQ everything!”), because as an infrastructure provider to the world, we want to give our customers the peace of mind that using Cloudflare ensures that their traffic is future-proofed against quantum adversaries.
But how does one accomplish such a massive migration at an organization of our size and scale? After all, cryptography is the base layer for almost all of the world’s digital systems, including the software services and the networking protocols that power our platform.
To drive our PQ migration, we have three key goals.
First, we want to help our product and engineering teams understand how cryptography is being used and how they should be upgrading it. This should cover both the upgrades to post-quantum encryption and to post-quantum authentication. Many of our products have already been upgraded to post-quantum encryption over TLS 1.3, but we Continue reading
When someone starts singing the Use Digital Twins to Test Your Network hymn (or, more recently, tells you how AI agents can do that to validate their ideas), ask them about these minor details. If they persist, point them (not that it would help) to this long list of gotchas.
That list just got longer: Arista cEOS container does not apply inbound ACLs to control-plane traffic (Arista vEOS VM does).
Bot mitigation is an adversarial game: attackers adapt, defenders respond, and the cycle continues. At Cloudflare, we stay ahead by combining visibility across our global network with signals from the client-side environment. At the network level, we analyze over 1 trillion requests per day to understand reputation, patterns, and anomalies across more than 20% of the web. On the client side, we’ve pushed detection deeper with Cloudflare Turnstile, which has evolved from a CAPTCHA replacement to a risk-based managed challenge that adapts the amount of friction needed to verify the user is authentic.
Today, Turnstile runs nearly 3 billion times per day on some of the most sensitive endpoints on the Internet, helping verify users at key moments like login, signup, and checkout. This improves protection on the most important areas of customer applications, but still leaves limited visibility into the rest of the application — how humans and bots actually interact across the full user journey.
This is the visibility gap we’re closing today with our launch of Precursor.
Precursor is a client-side, session-based verification system, built with privacy in mind, that uses dynamically injected JavaScript to continuously collect behavioral signals as visitors interact with your Continue reading
RSA and ECC, cryptographic algorithms that we’ve all relied on for decades, are vulnerable to the attack of sufficiently advanced quantum computers. Such quantum computers do not exist yet, but they seem to be coming sooner than expected. Luckily, the solution is already available: migrate to ML-KEM encryption and ML-DSA signatures, which are designed to be resistant to quantum attack. They were standardized in 2024 by the U.S. National Institute of Standards and Technology (NIST) after an eight-year open international competition.
The migration to post-quantum cryptography is in full swing now. At the time of writing, the majority of traffic handled by Cloudflare is already using ML-KEM encryption, and is thus secured against the threat to data posed by harvest-now-decrypt-later attacks. But encryption is only one part of the equation: to be fully secure against quantum computers capable of breaking classical cryptography, we aim to deploy post-quantum signatures to protect authentication systems from unauthorized access. We are targeting 2029 for Cloudflare to be fully post-quantum secure.
ML-DSA, the best all-around post-quantum signature scheme standardized today, has its downsides: it’s much larger on the wire, and many tricks we were able to perform with RSA and ECC simply cannot be Continue reading
Today, the UK government launched the Cyber Resilience Pledge: a voluntary framework inviting organizations to commit to foundational cybersecurity governance, board-level accountability, and comprehensive cybersecurity coverage across supply chains. Cloudflare is proud to join the pledge’s founding cohort of signatories and continue our long-standing work with the Department of Science, Innovation and Technology (DSIT), National Cyber Security Centre, and others to shape a more secure, future-ready digital economy for the UK.
The pledge's core pillars — democratizing security, leadership accountability, and radical transparency — have been at the heart of Cloudflare since day one. Instead of approaching this framework as a new set of commitments to meet, we see it as a welcome validation from the UK government of the security philosophy and principles Cloudflare has championed for over a decade. We are glad to see the rest of the industry moving in this direction.
This pledge is an important step, and it comes at a time of significant cyber risk. In the first quarter of 2026, Cloudflare's global network blocked an average of 234 billion cyber threats every day. Recently, we mitigated a hyper-volumetric DDoS attack that peaked at 31.4 Tbps. At the end of 2025, Cloudflare Continue reading
Original content is the lifeblood of conversations and curiosities. Imagine a world without it: we could find a thousand ways to regurgitate the same material that’s already been created, but we would witness the decline of fresh ideas and arguments.
Website owners fuel the ecosystem of ideas, news, and interesting tidbits, but they face the increasingly complex challenge of managing traffic to their websites and being paid for their content. While some bot traffic is clearly malicious, it isn’t always obvious when a particular AI crawler is helping or harming your business. To answer this, site owners need granular, reliable data to differentiate between traffic that provides value, and traffic that strains resources while eroding the foundation of their business model: actual humans consuming their content.
At Cloudflare, we hold a core belief: website owners have the right to control access to their content. We want to help website owners maintain their high-quality content and regulate AI traffic.
To provide much-needed clarity and help website owners take control, we’re excited to announce the new Attribution Business Insights dashboard — designed with business decision-makers and publishers in mind.
For decades, the business model of Continue reading
Cloudflare provides services that help run 20% of the web, but we don’t do it alone. Developers on our platform use a myriad of tools and services from other companies too. Cloudflare provides a rich API for our platform that enables developers to create automations, CI/CD, and integrations that glue together the various parts of their infrastructure. Earlier this month, we announced self-managed OAuth, making it easier for customers to create and manage their own OAuth clients for delegated access to the Cloudflare API.
Cloudflare isn’t new to OAuth. If you’ve used Wrangler, or used integrations from partners like PlanetScale, then you’ve already used it. However, until now, third-party OAuth was only available through a small number of manually onboarded integrations, and was not available to developers more broadly. That meant developers building their own integrations had to rely on API tokens, which are harder to manage and a poor fit for many delegated application flows.
Over the last year, we onboarded a growing number of early partners while improving the consent, revocation, and security model behind Cloudflare OAuth. But as our Developer Platform grew and agentic tools drove demand for delegated access, it became clear that opening Continue reading
On June 22, 2026, President Trump signed Executive Order 14409, "Securing the Nation Against Advanced Cryptographic Attacks." The order sets a December 31, 2030, deadline for federal agencies to transition their most sensitive systems to post-quantum encryption, and a December 31, 2031, deadline for post-quantum authentication. The EO also directs federal contractors to comply with post-quantum Federal Information Processing Standards (FIPS) by the end of 2030.
We welcome this executive order. The U.S. government has a long track record of using federal leadership and procurement to drive adoption of new technologies across the broader industry. We've seen this work with IPv6, with routing security and the Resource Public Key Infrastructure (RPKI), and with DNSSEC, and we’re glad to see this tradition continue with post-quantum cryptography.
The EO is especially important at this moment because the timeline for Q-Day, the day that quantum computers can break the public-key cryptography used across the Internet, has been accelerated. In April 2026, Cloudflare moved our own target for full post-quantum security to 2029, following research breakthroughs from Google and Oratomic. This EO updates guidance from 2024, when the National Institute of Standards Continue reading
A few weeks ago, we published our initial findings from Project Glasswing, looking at what happens when you point frontier security models at an enterprise codebase. We also explored how our defensive structures adapt to protect our infrastructure and customers from threats posed by frontier AI. Since then, the AI ecosystem has continued to shift rapidly — developers who've built tightly around a single model have already experienced what happens when that model is no longer available or gets superseded by a more capable one. These market shifts only reinforce our core thesis: no matter which underlying model is leading the pack on any given day, the future of agentic workflows will not be found in standalone models, prompts, or single-agent sessions.
Moving from a localized security "skill" to a continuous, fleet-wide scanning pipeline requires an architecture where models are treated as interchangeable components. Relying on a single model inherently limits defensive coverage, as the same system will tend to look at code paths through the exact same lens. To counter this, models should be frequently interchanged and cross-tested. By varying the models across the pipeline — such as using one model for initial discovery and an entirely different Continue reading