A DEEP DIVE INTO CLOUDFLARE'S SEPTEMBER 12, 2025 DASHBOARD AND API OUTAGE

Summary from the TLDR Web Dev newsletter

Cloudflare had a major outage of its dashboard and APIs on September 12 caused by a bug in its dashboard that triggered excessive calls to its Tenant Service API due to a problematic React useEffect hook, which coincided with a service update and overwhelmed the system. The Tenant Service handles API authorization, so when it became overloaded, it caused widespread 5xx errors across Cloudflare's APIs and dashboard for several hours.