Cloudflare outage on December 5, 2025
Cloudflare outage on December 5, 20252025-12-05Dane Knecht5 min readOn December 5, 2025, at 08:47 UTC (all times in this blog are UTC), a portion of Cloudflare’s network began experiencing significant failures. The incident was resolved at 09:12 (~25 minutes total impact), when all services were fully restored.A subset of customers were impacted, accounting for approximately 28% of all HTTP traffic served by Cloudflare. Several factors needed to combine for an individual customer to be affected as described below.The issue was not caused, directly or indirectly, by a cyber attack on Cloudflare’s systems or malicious activity of any kind. Instead, it was triggered by changes being made to our body parsing logic while attempting to detect and mitigate an industry-wide vulnerability…
