Cloudflare outage on November 18, 2025

On 18 Nov 2025, Cloudflare experienced a major global outage after a ClickHouse permission change caused a Bot Management feature file to include duplicate rows, doubling its size and exceeding a runtime feature-limit in the proxy (FL/FL2), which led to panics and widespread HTTP 5xx errors across core CDN/security services, Workers KV, Access, Turnstile, and the dashboard; despite initial suspicion of a DDoS, the event was not an attack, and recovery was achieved by stopping bad file generation/propagation, rolling back to a known-good file, and restarting services, with core traffic normalizing around 14:30 UTC and full restoration by 17:06 UTC.