When the Internet Stumbled Again: The Cloudflare Outage of 18 November 2025

Earlier yesterday, a major chunk of the internet went dark. Several high-profile platforms and websites experienced disruption, not because of a cyber-attack but because one of the key infrastructure providers of the internet itself hit trouble. The outage offers a powerful reminder: even the backbone services of the web aren’t immune, and businesses must be ready.

What happened, and when

On Tuesday 18 November 2025, early in the morning (US Eastern Time) the Cloudflare network began showing signs of distress. 

Around 6:40 a.m. ET, Cloudflare noted “internal service degradation” in one of its systems. 

• The company later identified that the cause was a spike in unusual traffic to one of its services, which caused network errors. Reuters

• According to Cloudflare’s update, a “configuration file … grew beyond an expected size of entries and triggered a crash in the software system that handles traffic for a number of Cloudflare’s services.” Financial Times

• By mid-morning the bulk of services were being restored, though some residual impacts lingered. The Washington Post

What do some of those terms mean?

• Configuration file: a text‐based file used by software to determine how it operates (which options are enabled, thresholds, etc.). When it “grows beyond expected size,” it can cause software to choke (exceed resource limits, get errors).

• Traffic spike: An unexpected surge in usage or requests (either legitimate or automated) to a service, which can overwhelm its capacity or routing logic.

• Internal service degradation: A status where the service is still running but experiencing higher error‐rates or slower response times; users may see failures or delays.

Who and what was affected

Because Cloudflare supports a large share of web traffic globally (estimates say around 20% of all websites depend on it). Financial Times That means when something goes wrong there, the ripple effects are large.

Some of the affected services

• ChatGPT (via OpenAI) — users logged errors and access issues. Reuters

• X (formerly Twitter) — experienced disruptions. Reuters

• Canva — image-editing and design service also impacted. Financial Times

• IKEA — global retailer whose website and services were touched. Financial Times

• Other platforms: gaming services, finance platforms, transit sites (e.g., NJ Transit) also reported issues. New York Post

Why it mattered

• Users globally saw “500 Internal Server Error” messages, “please unblock challenges.cloudflare.com to proceed” errors, and inability to log in or access key services. The Times of India

• Businesses relying on real-time online services were disrupted: staffing, customer-access, online transactions.

• It underscored how dependent modern business and consumer workflows are on a small number of core infrastructure providers.

Why this outage happens: the deeper issue

The root cause

Cloudflare traced the incident not to a malicious attack, but to internal software failure triggered by a configuration/bloat problem. Because one part of the system had grown unexpectedly and triggered cascading issues, traffic routing, security checks, and website delivery were compromised.

Why it spread

• Because Cloudflare acts as both a Content Delivery Network (CDN) and security provider (reverse proxy, distributed DNS, traffic filtering), many websites and apps depend on its infrastructure to deliver content and shield against attacks. When that stops working properly, those dependent systems falter.

• The fault occurred in a “control plane” type function, the management/configuration side, which then impacted the “data plane” (actual traffic delivery) for many services.

• The size and connection of Cloudflare’s network (330+ data centres globally) mean that issues can propagate fast.

The business implications

• A single vendor or single point of failure can create outsized risk.

• Even if your core system is separate, if you rely on third-party infrastructure (CDNs, security providers, DNS), you may still be vulnerable.

• Incident response needs to consider upstream dependencies, not just your own systems.

What this means for businesses & the key lessons

1. Map your dependencies

List which external services your business relies on (CDN, DNS, API providers). Ask: “If this service fails, what happens to our operations?”

2. Build redundancy where practical

• Use alternative providers or multi-provider strategies.

• For critical components (e.g., user authentication, content delivery), ensure fallback paths.

• A degraded mode (reduced functionality but still operational) is far better than full outage.

3. Test incident scenarios

Simulate failure of an upstream vendor. Confirm that switching to a fallback works and that communication with stakeholders is rapid.

4. Monitor upstream risk & communicate

Your infrastructure monitoring needs to include external dependencies. If a major provider reports “partial outage”, your business needs to react. Also: keep clients/users informed swiftly,  transparency builds trust.

5. Leverage managed expert support

Partnering with a provider who understands cloud, CDN and infrastructure risk can help you stay ahead of blind spots.

How Logixal helps protect you

At Logixal, we recognise that infrastructure risk reaches beyond your own data-centre or cloud account. We help our clients by:

• Conducting dependency audits (which providers are you using and how critical are they?).

• Designing multi-region/multi-provider architectures to mitigate single-vendor failure.

• Setting up alerting and failover strategies for upstream vendor incidents.

• Crafting business-continuity plans that include upstream failure (CDN, DNS, API provider) as a scenario.

Final thoughts

The 18 November 2025 Cloudflare outage may have lasted only hours, but its lessons will reverberate for much longer. It shows that even the infrastructure we assume will “just work” can falter, and when it does, the consequences ripple through consumer apps, enterprise services and public-sector systems alike.

In the age of cloud- and API-driven business, resilience is not optional. It means being prepared for when your provider’s provider struggles.

If you’d like to review your infrastructure’s resilience, or map your upstream dependencies, our team at Logixal is ready to help.