Cloudflare Latent Bug Causes Major Global Internet Outage

A widespread internet disruption on November 18, 2025, temporarily took some of the world’s largest online platforms offline, after Cloudflare confirmed that a hidden software flaw had been activated during a routine system update. Services, including ChatGPT, Claude, Spotify, and X, experienced downtime as traffic across Cloudflare’s network degraded. The company stressed the incident was caused by an internal configuration issue and not a cyberattack.

What Caused the Cloudflare Outage?

Cloudflare users began reporting issues on Tuesday morning as popular applications became inaccessible or slowed significantly. By 8 a.m. ET, Cloudflare published an alert on its status page, and engineers began rolling out a fix. Within two hours, the company marked the issue as resolved, although some dashboard-related disruptions continued.

Cloudflare CTO Dane Knecht later explained that a “latent bug” in a system supporting the company’s bot mitigation service was triggered during a standard configuration change. The resulting process failures cascaded across Cloudflare’s global edge network, leading to widespread service degradation.

A latent bug refers to a piece of faulty code or logic that can exist undetected for long periods. It only surfaces under specific operating conditions, such as an update or configuration alteration, making it difficult to anticipate during testing.

Cloudflare’s Response and Public Apology

In a statement published on X, Knecht apologised to Cloudflare’s customers and the wider internet community, acknowledging the significant impact of the outage. He noted that the company “failed our customers and the broader internet” and added that Cloudflare is committed to preventing a recurrence. A more detailed technical review is expected to follow.

Even after primary services were restored, Cloudflare reported that some users continued experiencing issues accessing the Cloudflare dashboard. A separate fix is being prepared to address these remaining authentication and interface problems.

Why Cloudflare’s Outage Matters

The incident underscores a broader concern about the structural fragility of the internet. Cloudflare provides services to roughly 20% of all websites, making it one of the largest infrastructure companies on the web. When a provider of this scale suffers a disruption, the ripple effects extend far beyond its immediate customer base.

The outage also follows a high-profile service failure at Amazon Web Services (AWS) earlier this month, reinforcing the recurring risk of systemic bottlenecks created by concentrated infrastructure control.

A Security Tool at the Centre of the Failure

Adding to the irony, the source of the outage was a failure in Cloudflare’s bot mitigation system, technology designed to protect customers from malicious automated traffic. In this case, the protective system itself became the origin of instability, illustrating how complex defensive architectures can introduce unexpected points of failure.

What Happens Next?

Cloudflare has committed to publishing a full technical breakdown detailing why the bug remained undetected and how the update triggered a cascading effect. The company is also expected to review its internal validation processes for configuration changes, particularly for systems that support mission-critical traffic routing.

While most services are back online, Cloudflare continues working on residual dashboard issues and will release follow-up updates as fixes are deployed.