On November 18, 2025, Cloudflare's network experienced significant disruptions due to a permissions change in their database system, which inadvertently caused a feature file used by their Bot Management system to double in size, exceeding the software's size limit and resulting in failures across their network. Initially misdiagnosed as a potential DDoS attack, the core issue was identified and resolved by reverting to an earlier version of the feature file, thereby restoring normal traffic flow by 14:30 UTC. The incident affected several Cloudflare services, including their CDN, Workers KV, and Access, leading to elevated error rates and authentication failures, although email delivery remained largely unaffected. The outage resulted from duplicated feature rows in configuration files due to a change in ClickHouse query behavior that expanded access permissions; this caused the Bot Management system to exceed its feature limit, triggering system failures. Cloudflare has since undertaken measures to harden their systems against similar failures, emphasizing the critical need for resilience in their network architecture to prevent such widespread impacts in the future.