An hours-long outage at Cloudflare on November 18, 2025 briefly knocked many major websites offline and left others struggling with unstable service. The disruption started as an “internal service degradation” and turned into repeated waves of downtime as systems came up and failed again. Many organizations found that they couldn’t easily move away from Cloudflare because they also relied on it for DNS, or because the management portal itself was unreachable. Those that did pivot around Cloudflare often had to expose their origin infrastructure directly to the internet, temporarily losing protections like web application firewalls, bot filtering, and other controls that normally sit at Cloudflare’s edge. Security experts describe that window as an accidental penetration test, where attackers suddenly saw long-hidden targets and ramped up credential stuffing, injection attempts, and other OWASP Top 10 style attacks while defenses were weakened.

The incident is framed as a learning moment rather than just a technical failure. Practitioners urge organizations to mine their logs from the outage period, asking what controls were bypassed, what emergency DNS or routing changes were made, who approved them, and whether staff quietly turned to personal devices, shadow IT, or ad-hoc tunnels to stay productive. They also stress the need to unwind any “temporary” workarounds before they become permanent blind spots. Cloudflare’s own postmortem says the outage wasn’t caused by an attack, but by a misconfigured database permission that caused a bot-management feature file to balloon in size and propagate across the network, overwhelming systems. With Cloudflare estimating it serves roughly one-fifth of all websites, and so much of the web concentrated on a few big providers, the episode is a reminder that over-reliance on a single vendor is itself a security risk. Experts recommend splitting WAF and DDoS protection across multiple zones, using multi-vendor DNS, segmenting applications so one provider’s outage can’t take everything down, and continuously monitoring for dangerous single-point dependencies.

‍

Source: https://krebsonsecurity.com/2025/11/the-cloudflare-outage-may-be-a-security-roadmap/