Klaviyo change history: Cloudflare incident disrupting onsite events

Klaviyo reported a major Cloudflare-related outage: onsite forms appeared, but requests, events and subscriptions did not process; preference pages errored and API calls returned 403s. It started 2025-11-18 13:58 UTC and resolved 2025-11-18 19:06 UTC, lasting 5 h 7 min. Fixes were implemented, and all affected components were operational at resolution.