Cloudflare Explains Tuesday’s Outage That Temporarily Took Down ChatGPT

A routine configuration update turned into a global digital crisis on Tuesday, November 18, as a massive outage at internet infrastructure giant Cloudflare took down significant swathes of the web. The disruption, which lasted nearly four hours, rendered major services including ChatGPT, X (formerly Twitter), Canva, and Spotify inaccessible to millions of users worldwide, underscoring the fragility of the centralized internet.

Quick Take: The Outage by the Numbers

• Timeline: The incident began at 11:20 UTC (5:20 PM BST) and core traffic was restored by 14:30 UTC (8:30 PM BST).

• Root Cause: A “latent bug” in a bot-management configuration file, not a cyberattack.

• Scale: Reports of outages spiked to over 11,000 in the US alone within the first hour on Downdetector.

• Market Impact: Cloudflare (NET) shares dipped approximately 2.8% during morning trading following the crash.

• Key Services Hit: OpenAI (ChatGPT), X, Spotify, Grindr, Uber, and Claude.

The ‘Latent Bug’ That Broke the Internet

Cloudflare, which acts as a reverse proxy and security shield for nearly 20% of all websites, confirmed late Tuesday that the blackout was self-inflicted. Contrary to early speculation on social media, the collapse was not caused by a Distributed Denial of Service (DDoS) attack.

According to a technical post-mortem released by Cloudflare, the chain of events began with a change to a database system’s permissions. This seemingly minor tweak caused a “feature file”—a crucial component used by Cloudflare’s Bot Management system to identify threats—to suddenly double in size.

This failure triggered a cascade. The corrupted file was propagated across Cloudflare’s global network, causing servers responsible for routing traffic to crash. In a cruel irony, the system designed to protect the web from traffic surges (DDoS attacks) was brought down by an internal file that grew too large, mimicking the symptoms of an attack.

Widespread Impact: From AI to Social Media

The outage was felt immediately and acutely across the globe. Users attempting to access ChatGPT were met with a “Bad Gateway” 502 error or a message demanding they “unblock https://www.google.com/search?q=challenges.cloudflare.com.”

OpenAI confirmed the disruption on its status page, noting “elevated error rates” that left its millions of daily users unable to generate text or access chat history.

The blast radius extended far beyond AI:

• Social Media: X (Twitter) users reported inability to load timelines or post updates.

• Productivity: Design platform Canva and project management tools went dark, disrupting workflows for businesses globally.

• Streaming & Services: Spotify, Uber, and even the New Jersey Transit system faced intermittent connectivity issues.

• Gaming: Titles like League of Legends and Valorant saw login servers fail.

Data from network monitoring service Downdetector showed a vertical spike in problem reports starting at 6:30 AM ET (11:30 UTC), affecting users from New York to London and Dhaka.

Official Response: “We Let You Down”

Cloudflare executives moved quickly to own the mistake. CEO Matthew Prince and CTO Dane Knecht took to social media and the company blog to apologize.

In a statement, the company said:

Engineers initially suspected a “hyper-scale DDoS attack” due to the pattern of traffic drops and server failures. However, once the team identified the oversized feature file as the culprit, they manually reverted to a previous version, stopping the crash loop.

Dane Knecht, Cloudflare’s Chief Technology Officer, described the issue as a “latent bug,” meaning the software flaw had existed harmlessly in the code until the specific conditions of Tuesday’s file update triggered it.

Expert Analysis: The Centralization Risk

This incident has reignited the debate over the internet’s reliance on a handful of “backbone” providers. When a single entity like Cloudflare, Amazon Web Services (AWS), or Azure falters, the ripple effects are catastrophic.

“Tuesday’s outage highlights how much of the modern web depends on a small number of infrastructure companies,” noted a report from the Economic Times. While these services provide essential speed and security, they also represent single points of failure.

For businesses in Bangladesh and South Asia, where reliance on cloud-based tools like WhatsApp and global SaaS platforms is growing, the outage served as a stark reminder of vulnerability. Local tech firms reported temporary acces issues to their hosted services abroad, though domestic internet infrastructure remained largely unaffected.

What to Watch Next

Cloudflare has stated it is implementing “system hardening” measures to prevent a recurrence. This includes:

1. Code Audits: Reviewing file-size limits in legacy software to prevent similar buffer overflows.

2. Testing Protocols: stricter sandboxing for database configuration changes before they are pushed to the global network.

3. Client Reassurance: Cloudflare will likely face tough questions from enterprise clients, particularly those with strict Service Level Agreements (SLAs) regarding uptime.

While the internet is fully back online as of Wednesday morning, the “Cloudflare Crash of 2025” will likely be a case study in reliability engineering for years to come.