Cloudflare is down again, temporarily impacting hundreds of websites, including Canva, Zoom and Claude, among various others, unreachable on Friday (December 5). Cloudflare CTO Dane Knecht confirmed the technical problems, saying that the company is working on a fix and the websites should soon be coming back online. He also shared the “root cause” of what led to the worldwide outage. The internet infrastructure provider deployed corrective measures.

Root Cause: Disabling logging features

In a post on X (formerly Twitter), Knecht said, “We are aware of the issue impacting the availability of Cloudflare’s network. It was not an attack; root cause was disabling some logging to help mitigate this week’s React CVE.”“Will share full details in a blog post today. Sites should be back online now, but I understand the frustration this causes and the work being,” he added.He previously posted that the company is “closely tracking the React RSC vulnerability.” If you deploy on Cloudflare Workers, you are protected. The Workers security model prevents this exploit at the runtime layer. For users that rely on WAF to protect self hosted applications more variants of this exploit are already surfacing and we are evaluating each one. As always the best way to stay protected is to upgrade to the patched versions of React and NextJS as soon as possible,” he added. Later, the cmopany rolled out “additional mitigations” to protect more customers. Meanwhile, the company posted on its status page that a fix has been resolved, the services are back online, and the team is monitoring the situation.“Cloudflare services are currently operating normally. We are no longer observing elevated errors or latency across the network. Our engineering teams continue to closely monitor the platform and perform a deeper investigation into the earlier disruption, but no configuration changes are being made at this time,” the company said (at the time of writing).“At this point, it is considered safe to re-enable any Cloudflare services that were temporarily disabled during the incident. We will provide a final update once our investigation is complete,” the company added.

Second Cloudflare outage in a month

This is the second such outage in a month’s time. Previously, on November 18, Cloudflare went down for hours, impacting major websites worldwide. At that time, the CTO said, “A latent bug in a service underpinning our bot mitigation capability started to crash after a routine configuration change we made. That cascaded into a broad degradation to our network and other services. This was not an attack.”Knecht stressed that the extent of the issue and the time required for resolution were “unacceptable.”