What caused Cloudflare outage that disrupted half of Internet?

Multiple global online platforms, including X, ChatGPT, Spotify, and numerous other websites that heavily rely on Cloudflare, for cyber security and traffic management, experienced a huge outage on Tuesday, November 18, 2025.

The outage has sent shock waves, turning the internet world into complete chaos.

The real reason for the internet chaos was a little-known technology term, a ’latent bug,’ as described by Cloudflare CTO, Dane Knecht.

As the confusion escalated, Cloudflare’s Chief Technology Officer, Dane Knecht, took to X (formerly Twitter) to explain what caused the internet outage.

He detailed down, writing, ”The disruption was caused by a 'latent bug.'"

He brushed off any cyberattack, spiraling into global disruption.

He added, “In short, 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.”

However, Knecht promised customers that such an outage would never happen again: “Work is already underway to make sure it does not happen again, but I know it caused real pain today.”

What is a 'latent bug'?

A 'latent bug,' in its simplest definition, is a hidden flaw in a system.

It can sit quietly for months or even years without causing any visible issues.

It’s almost impossible to detect these bugs because they don’t show up during routine testing.

Normally, they (latent bug) only abruptly surface when a very rare combination of conditions comes together.

Once activated, the bug can cause unexpected and potentially widespread system failures.