On October 19, 2026, we learned about eMudhra’s eight shockingly weak keys: where eMudhra was trusted to pick a 115-digit number for their virtual combination lock protecting the Internet, they picked the number 4. Not even four digits, just the number 4. The other seven keys were similarly weak: 56, 66, 115, 155, 156, 230 and 237.
The next day, we wrote a blog post on the immediate action we took to mitigate this leak, and what customers needed to do on their end to stay secure. Now, we are sharing a more in-depth follow up on the evidence we’ve seen of exploitation, and the progress seen on visitors patching their systems.
Let's start with the scale of the problem. A certificate authority (CA) with weak keys this serious is unprecedented, and the potential consequences are significant. While there have been plenty of compromised certification authorities in the past (such as DigiNotar, TÜRKTRUST, and TrustWave), access to their keys has always been contained to a degree; these incidents gave a limited set of attackers or organizations the ability to issue fraudulent certificates. The eMudhra incident is fundamentally different; the affected intermediate private keys could be recovered almost Continue reading
Today, Cloudflare services for private origins is generally available. Point a proxied DNS record at a private IP, and Cloudflare reaches the origin over your existing Cloudflare One connection. Your origin stays private, while web application firewall (WAF), caching, bot management, and Workers work just as they do for public origins.
In June, we launched this capability in closed beta to address a problem we kept hearing from customers: Their internal APIs, AI agent backends, MCP servers, and operational tools weren’t built to face the Internet, but those services still need to accept requests from partners, customers, or agents over the Internet. Before the beta, putting Cloudflare in front of these services meant exposing a public IP, opening a firewall port, or running cloudflared alongside the origin.
Those requirements often left private applications without the same protections and controls they used for public applications, including WAF, bot management, rate limiting, caching, traffic acceleration, rewrites, and Workers.
During the closed beta, eligible customers requested access through their account team. Today, we’re opening access beyond that beta group.
Point a proxied A or AAAA record at a private IP, and Cloudflare’s application services work Continue reading
Welcome to the 26th edition of Cloudflare's DDoS Threat Report. This edition covers the third quarter of 2026 — July, August, and September — and returns the series to its quarterly cadence following the combined H1 2026 volume. The analysis is produced by Cloudforce One, Cloudflare's Threat Intelligence organization, providing a comprehensive analysis of the evolving threat landscape of Distributed Denial of Service (DDoS) attacks based on data from the Cloudflare network.
The Internet can feel invisible when everything is working normally. But when connectivity breaks, the many systems it depends upon become evident in an instant. Because Cloudflare’s global network handles more than 20% of the web’s traffic, it offers a unique perspective of how Internet traffic is behaving. When failures in infrastructure, power, policy, or security disrupt access to the Internet, Cloudflare Radar can observe the impact by monitoring traffic to our customers. Each quarter, we review the disruptions detected and annotated on Radar, highlighting what happened, where it happened, and the broader conditions that shaped each event.
In this post, we examine the major categories of Internet disruptions observed during the third quarter of 2026, including government-directed shutdowns, power outages and natural disasters.
Between July and September, Internet disruptions were largely driven by failures in the systems the Internet depends on. Power grids failed in Cuba, Honduras, Guam, Ukraine, and several other countries. Natural disasters damaged electricity and telecommunications infrastructure from Nepal to Colombia. Government-directed shutdowns remained the most frequent source of disruption, driven largely by exam-related shutdowns in Iraq, while renewed conflict in Ethiopia’s Tigray region showed how quickly connectivity can become part of Continue reading
Last week was one for the Internet security history books. First, eight eMudhra intermediate certificates were compromised, creating the possibility of forged certificates that could be used to impersonate servers. Then came php2shell: serious vulnerabilities in PHP, the runtime behind a large portion of the Web.
Cloudflare worked around the clock as these events unfolded to protect our customers and help protect the Internet. We shipped client updates and multiple mitigations, updated our web application firewall (WAF) with new rules to block attackers from exploiting the PHP vulnerabilities, and introduced a new feature called full transaction detection.
As always in situations like this, these new capabilities were made available on all plans, including Free.
Protecting systems from vulnerabilities like these is always an ongoing process, not a one-time event. The widespread adoption of AI allows attackers to discover new vectors with unprecedented speed and efficiency, so collecting real-world data to test our assumptions and strengthen defenses is essential.
That’s why today we're launching the Cloudflare PHP Capture the Flag challenge, run through our Bug Bounty program. We've put a deliberately vulnerable PHP installation behind our WAF, and we're inviting security researchers Continue reading
On September 8, 2026, we were alerted by a security researcher, Gadi Evron from Knostic, to a tenant isolation issue affecting the GLM-5.3 Workers AI model (@cf/zai-org/glm-5.3) starting on August 27, 2026. We have remediated the issue, and we restored the model on September 9. We have confirmed that no other model hosted on Workers AI was affected.
Between August 27 and September 9, a small number of customers using the GLM 5.3 Workers AI model received responses that contained data from other customers' requests made to the same model shortly before theirs. In total, 155 responses were affected, all to prompts longer than 681,280 tokens.
After excluding our own testing and the researcher's, the requests we identified are consistent in timing and volume with ordinary long-context use, not with someone repeatedly exploiting the bug. We found no evidence of deliberate exploitation.
Today we are publishing this report alongside a post from SGLang, the open-source inference engine that we use, as a coordinated disclosure. This post describes the bug that caused this issue, our response timeline, and the subsequent hardening we have conducted on our production SGLang deployments. We also detail our continued efforts with Continue reading
A video player seeking to the middle of a movie asks for a few megabytes. Under our old range caching, that one request could make Cloudflare pull 128 MiB from the origin and move it between data centers, sometimes after the viewer had already left. Range requests are how large files get delivered, and caching them naively easily leads to wasted network bandwidth and wasted disk operations when running a CDN at scale.
So we rebuilt how our cache handles them. For R2, Cloudflare's object storage, p99 time to first byte dropped by about half, and a follow-up improvement cut tiered cache traffic for R2 and similar workloads by about 6%.
Today, we're making that new implementation available as Origin Range Requests, a self-service feature on all plans. There's no range size to tune and no need to contact support. Turn it on with a Cache Rule, and Cloudflare handles the rest.
An HTTP range request asks for part of a resource instead of the whole resource. The client sends a normal GET with a Range header:
GET /movie.mp4 HTTP/1.1
Host: example.com
Range: bytes=1048576-2097151If the server supports the Continue reading
Today, Cloudflare is launching a post-quantum geographically restricted key manager in support of our Data Localization Suite (DLS) in closed beta. This new PQ GeoKey Manager is a cornerstone of Cloudflare’s data sovereignty solutions, making sure that a customer's decryption keys are only accessible in their chosen geography. GeoKey Manager implements this by wrapping each decryption key such that it can only be decrypted by Cloudflare servers that are located in the allowed geography.
While general availability (GA) is planned for Q1 2027, today’s launch is an important milestone on our journey to support our customers’ data sovereignty goals while also migrating all Cloudflare products to post-quantum (PQ) cryptography.
Governments, financial institutions, healthcare providers, and defense organizations process highly sensitive data that can remain sensitive for years or decades after it is produced. Encryption is often required to protect this data. When classical, public-key encryption is used, adversaries do not immediately need a quantum computer today to put that data at risk: they can store the ciphertext and retain them until quantum computers can break the public key cryptography protecting it — an attack strategy known as harvest now, decrypt later.
For organizations with geographic requirements, resisting that threat is Continue reading
For ten days, auditors appointed by the Korea Internet & Security Agency (KISA) sat together with us and worked through 80 controls. That is what it took for a company headquartered in the United States, operating a global network serving Korean users, to be certified in South Korea. Cloudflare has now obtained South Korea's Information Security Management System (ISMS) certification under the ISMS-P framework.
For customers in Korea, this is more than a compliance checkbox. It is evidence that Cloudflare's security and privacy program has been examined not only for whether our controls exist, but for how they operate in the context of Korean law, the Korean language, and the particular expectations of Korean regulators.
The most visible result of this work is the Cloudflare account sign-up page. In most parts of the world, the line that sits above the sign-up button reads: "By continuing, I agree to Cloudflare's terms, privacy policy, and cookie policy."
A user signing up from South Korea sees something different. The Korean experience is triggered by the country selected at sign-up and by IP geolocation from within South Korea, and it breaks the same Continue reading
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
AI can write code and pass the bar exam, but it still struggles to buy a pair of shoes online.
That’s because websites were built for humans, not agents. Most agents that shop for someone today work from a site’s HTML — they look at the page, guess which button does what, click, and try again when they get it wrong. This process is slow, uses a lot of tokens, and something as seemingly innocuous as a theme change can break it.
Enter WebMCP: a browser standard from Google that gives AI agents structured tools on a page, like search_products. Instead of hunting for buttons, the agent calls the exact tool it needs directly, making shopping faster, cheaper, and far more reliable. Because WebMCP is still an experimental proposed browser standard in early preview, it’s currently available behind experimental Chrome flags (chrome://flags/#enable-webmcp-testing), in Chrome Origin Trials, in some agentic browsers, and across developer environments like Cloudflare Kitesurf.
In August, we launched edge implementation of WebMCP in beta. Turn it on, and Cloudflare injects a tiny script at the edge to make those tools available automatically, without site owners writing a single line of code.
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
Cloudflare and VoidZero are now working with Max Schwenk of Owner.com on tsrs, a Rust port of the TypeScript compiler. We are doing this work in close collaboration with the TypeScript team, and incubating tsrs as part of the Oxc JavaScript compiler toolchain.
Our goal is to help developers spend less time waiting for their code to be checked and more time building. Making TypeScript faster and more memory-efficient also helps bring complete development environments to more places, including right in your browser.
To be clear, we are not forking TypeScript. We believe the TypeScript team should remain in full control of the language’s design and direction. They have maintained a long-term vision while guiding TypeScript’s adoption across the JavaScript community. We do not want to change that.
The TypeScript team can move quite fast on many things, but for some features they may spend years intentionally exploring options and making prototypes before picking the right implementation. A Rust port has to follow those decisions closely, or it will eventually fall apart and become incompatible. We have to preserve the TypeScript language strictly based on its original implementation – and the TypeScript team should remain solely responsible for Continue reading
When we previously blogged about our AI code reviewer in April, an average review cost a palatable $1.19. By the end of August, that figure had shot up to about $2.46. We hadn't made any significant architectural changes: the coordinator was still handing work to the same set of specialist reviewers, and the same risk tiers decided how intensive of a review we gave.
Around mid-September we tasked our agents with working out where those tokens were going and cutting them — aggressively. With code quality at high effort, the average review now costs just $0.77, down 68% from the $2.43 it averaged over our two most expensive weeks before we started. Our main goal was to cut costs, but as part of this work we also managed to optimize the reviewer, so that the median review now takes just 1m 32s instead of the 4m 09s it took before.
About 40% of the savings came from changes and optimizations to the reviewer's code, and the rest from experimenting with which models we use and how much effort they put in.
The chart below shows the cost of an Continue reading
Today, we're announcing a preview of a new class of System One-style models: extraction models. Our first one, Clairic, is available hosted on Workers AI as @cf/cloudflare/clairic.We intend to release the model open-weights soon. Clairic is an extraction model that is able to extract, compute, estimate, and forecast values from unstructured inputs — all at a significantly higher accuracy, faster latency, and cheaper cost than traditional LLMs.
When System One models were announced by TypeSafe a month ago, it took the industry by storm. As referenced by TypeSafe in their blog and defined by Daniel Kahneman’s book Thinking, Fast and Slow, a System One model should be fast and precise, which contrasts a System Two model that is capable of deliberate reasoning (like LLMs). With this, TypeSafe introduced Jev — a model that is purpose-fit for a specific use case, and priced accessibly given its niche domain. It excelled where LLMs failed, helping users make decisions based on probabilities and well-typed outputs. The introduction of Jev prompted people to start thinking about a new class of models that were not LLMs and how to integrate them into their workflows.
We were inspired by the concept of System One models and 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.”
Every secure web gateway on the market works the same way: traffic matches a condition. A terminal action fires. Allow, Block, Isolate, Log. This model has been the foundation of network security for nearly 30 years, and it handles the common case well. But it has a ceiling, and customers with complex environments hit that ceiling regularly.
Earlier this year, we shared our vision to build a truly programmable SASE platform. We also outlined how the term programmability has become diluted by the security industry. Most vendors claim programmability because they have public APIs, Terraform providers, webhooks, and alerting. Cloudflare offers all of those things too, but that’s not enough. True programmability means running your own code — arbitrary logic that you wrote for your specific environment — inline in the policy evaluation path, at the moment a security decision is made.
Today, we’re excited to announce Cloudflare is bringing true programmability to Cloudflare Gateway and DLP (Data Loss Prevention) by integrating it with the entirety of our edge computing platform. We are releasing a new type of Gateway action, Forward, and custom validation functions, available to all Zero Trust plans. These capabilities allow you to use a Cloudflare Worker Continue reading
VoidZero's tools such as Vite, Vitest, Oxc, and Rolldown — bundled in one toolchain as Vite+ — have made frontend development faster, but building full-stack applications requires more than just a tooling stack. These applications need server routes, databases, local development environments, and a fast and easy way to deploy ideas to production.
We’re excited to open-source three new products that bring server routing, typed data access, and Cloudflare deployment into a unified Vite workflow.
The CLI deploys apps built with the SDK to the Platform. All three products are open-sourced as a single JavaScript package and Vite plugin that you can install via npm install void. With Void, you can build your server and client together, carry types from your database to the UI, and let Void automatically provision the Cloudflare resources that your app uses.
We originally set out to build a single, private platform for all users to deploy apps to. After VoidZero joined Cloudflare, we Continue reading