A little-known issue, a ‘latent bug,’ is being blamed for the massive disruption that impacted major platforms like X, ChatGPT, and Spotify on November 18, 2025.
On Tuesday, November 18, 2025, a significant outage took down several major online services that depend on Cloudflare for cybersecurity and traffic management. Platforms including X, ChatGPT, and Spotify, among many others, were affected, causing widespread chaos across the internet.
Cloudflare’s Chief Technology Officer, Dane Knecht, took to X (formerly Twitter) to provide an explanation for the outage, stating that the root cause was a ‘latent bug.’
Knecht clarified that the disruption was not the result of a cyberattack, but rather an issue that arose after a routine configuration change. He explained, “A latent bug in a service supporting our bot mitigation capability started crashing after the update. This triggered a cascading effect that led to the broader service degradation. This was not an attack.”
Knecht also reassured customers, saying, “Work is already underway to prevent a recurrence, but I understand the impact it had today.”
What is a ‘Latent Bug’?
A ‘latent bug’ refers to an undetected flaw in a system that remains hidden for extended periods, sometimes even years. These bugs are difficult to identify during routine testing because they don’t manifest until a specific and rare set of circumstances triggers them. Once activated, a latent bug can lead to unexpected system failures, sometimes on a large scale.
Nice article! I especially liked the actionable checklist.