Another Cloudflare Outage Raises Fresh Concerns

Cloudflare has suffered its second major service outage in less than a month, briefly taking a substantial portion of the internet offline and prompting renewed questions about the resilience of the infrastructure many organisations now rely on.

Friday 5 December Outage

This latest incident occurred on Friday 5 December, when websites around the world began returning blank pages, stalled login screens and 500 error messages from around 08:47 GMT. Cloudflare confirmed that the problem affected part of its global network and that a significant number of high profile customers were impacted. Although services were largely restored by 09:12, the disruption was extensive enough to affect millions of users and thousands of online businesses during a busy weekday morning.

What Happened And Why Did It Spread So Quickly?

Cloudflare acknowledged shortly after the incident that the outage was caused by an internal change to how its Web Application Firewall processes incoming requests. The change had been deployed as part of an emergency response to a newly disclosed security vulnerability in React Server Components. The flaw, widely discussed across the software industry, could allow remote code execution in some applications built using React and Next.js. Cloudflare introduced new rules to help shield its customers from potential exploitation while they applied their own patches.

A Bug Was Triggered

During that process, a long standing bug in how the Web Application Firewall parses request bodies was triggered under the specific conditions created by the mitigation. This resulted in errors being generated within parts of Cloudflare’s network responsible for inspecting and forwarding traffic. In practice, it meant that requests processed through those systems began failing, which is why so many sites appeared blank or unresponsive.

Not A Cyber Attack

Cloudflare’s Chief Technology Officer commented publicly that this was not the result of an attack and was instead linked to logging changes implemented to help address the React vulnerability. The company has since published a technical summary of the issue, stating that it was working on a full review to prevent similar failures from recurring.

The speed of the disruption reflected Cloudflare’s central role in global web infrastructure. For example, the company provides security, performance optimisation and traffic routing services for a large proportion of internet services. This means that when a fault is introduced in a critical part of its platform, the effects can cascade quickly across many unrelated industries and geographies.

Which Services Were Impacted?

Reports from affected organisations and users indicated that large platforms such as LinkedIn, Zoom, Canva and Discord were among the most prominent names disrupted. E commerce providers including Shopify, Deliveroo and Vinted also experienced problems. Media outlets and entertainment platforms saw outages, as did financial services and stock trading apps in some regions. Ironically, even DownDetector, the independent website that tracks service outages, was temporarily unavailable because it also runs on Cloudflare’s network.

For many businesses the disruption manifested as failed page loads, broken checkout journeys or services timing out without explanation. It should be noted that, although the outage was brief, these symptoms can have very real impacts. For example, retailers risk abandoned purchases, subscription platforms face customer frustration and organisations offering time critical services can see immediate operational strain.

How This Compares With The November Outage

The December outage arrived only weeks after Cloudflare’s previous incident on 18 November, which was far longer and affected a wider range of services. That disruption began around midday UTC and took several hours to fully resolve.

Cloudflare later explained that the November issue stemmed from an automatically generated configuration file used by its Bot Management system. A change to database permissions caused the file to grow far beyond its intended size. When the oversized file was synchronised across the network, it caused a core traffic routing module to fail repeatedly. Major services including X, ChatGPT, Spotify and large gaming platforms all experienced significant downtime.

Both The Results of Internal Changes

It seems, therefore, that the two outages were technically unrelated. The November incident was caused by a configuration file that overwhelmed a key proxying process, while the December disruption was caused by a logic error triggered within the Web Application Firewall. However, what links them is that both were the result of internal changes aimed at improving security and performance, and both exposed fragilities within a highly automated global system.

Reactions From Cloudflare And The Wider Industry

Cloudflare has stated publicly that any outage of this scale is unacceptable and has acknowledged the frustration caused to customers. After the November incident, its chief executive promised a series of improvements to configuration handling, kill switches and automated safety checks. The fact that a second issue occurred so soon afterwards has prompted visible concern from customers and industry observers about the platform’s change control processes.

The Danger Of Relying On A Small Number Of Infrastructure Providers

Security experts have emphasised the broader lesson here, i.e., that many organisations now rely heavily on a small number of global infrastructure providers. Cloudflare’s size and technical capabilities offer benefits in terms of speed and protection from attacks, yet this scale also creates single points of failure. If a major provider experiences a fault, thousands of websites and applications can be disrupted almost instantly.

Industry groups have urged organisations to reassess their resilience strategies. Some policy specialists argue that businesses should identify where they rely on a single vendor for critical operations and explore ways to diversify. This might involve adopting multiple cloud providers, splitting content delivery across different networks or architecting applications so they degrade gracefully rather than fail outright when a dependency becomes unavailable.

Customers And Competitors

For Cloudflare’s customers, the December outage reinforces the need to balance performance gains with risk planning. Many organisations use Cloudflare for security filtering, caching, bot protection and traffic routing, meaning a failure in any of those layers can have immediate consequences for availability.

Also, competitors in the content delivery and cloud security sector may see renewed interest in multi provider approaches. This does not necessarily mean businesses will move away from Cloudflare, given its extensive footprint and capability, but it is likely to encourage more organisations to build redundancy around critical services.

Regulators are also likely to take note of what has happened at Cloudflare. For example, European and UK frameworks focusing on operational resilience, such as NIS2 and DORA, place increasing emphasis on understanding and mitigating third party risk. Repeated outages at a major provider may strengthen the argument for closer oversight of critical internet infrastructure and more transparent reporting requirements.

What Happens Next?

Cloudflare has said it will publish a full post incident analysis and will continue making changes to improve reliability across its platform. The company has already committed to reviewing how new security mitigations are validated before deployment, in addition to strengthening internal safeguards that determine how changes propagate across the network.

For customers and other stakeholders, the incident is another reminder that internet resilience depends not only on defending against attackers but also on managing the risks introduced by routine operational changes. The growing complexity of web infrastructure has made this increasingly challenging, and the recent outages have placed long term operational resilience firmly back on the agenda.

What Does This Mean For Your Business?

The pace of software change, the pressure to react quickly to new vulnerabilities and the scale at which providers now operate mean that even well intentioned updates can clearly create unexpected instability. This latest incident from Cloudflare shows how a single adjustment deep inside a security layer can move rapidly through global systems and affect businesses with no direct connection to the underlying flaw. It also reinforces why resilience planning needs to be treated as a strategic priority rather than an operational afterthought.

UK businesses, in particular, face a growing need to understand how their digital supply chains actually function. Many organisations depend on Cloudflare without realising how many of their core services sit behind it. The outage demonstrated that customer experience, revenue and even internal operations can be affected within minutes if one vendor encounters a problem. These short disruptions may not make headlines for long, yet they expose gaps in continuity planning that boards and technology teams are being pushed to close, especially as regulators sharpen their expectations around third party risk.

Although Cloudflare’s competitors may now really want to highlight the benefits of multi provider architectures and the reduced exposure this can offer, the practical reality is that Cloudflare’s scale, speed and security tooling remain difficult to replicate. Most organisations may not currently be planning to abandon the platform but they may be looking for ways to introduce redundancy around it, whether by spreading workloads, adding backup routing options or designing services that fail more gracefully when a dependency falters. In other words, the market is now moving towards diversification rather than replacement.

Other stakeholders have lessons to learn from all this as well. For example, regulators will continue scrutinising outages that affect large sections of the internet, particularly where they touch financial services, transport or healthcare. Also, investors will look at whether Cloudflare can demonstrate consistent improvements after two incidents so close together. Developers and security teams across the industry may now reflect on the risks involved in rolling out urgent protections at speed, especially when the underlying software landscape is evolving as quickly as it is today.

Cloudflare remains a central pillar of global internet infrastructure, and that reality brings both advantages and pressures. Although pretty inconvenient and costly to many businesses and their users, the recent outages do not change the importance of Cloudflare, but they do highlight how essential it has become to strengthen resilience around the entire ecosystem. This means that organisations that choose to invest in understanding their dependencies and designing for failure may be better positioned to handle future shocks, whatever their source, and will place themselves on far stronger footing as digital systems continue to grow in complexity.