Cloudflare outage on December 5, 2025
6 days ago
- #Cloudflare
- #Web Security
- #Network Outage
- Cloudflare experienced a network failure on December 5, 2025, lasting ~25 minutes, impacting ~28% of HTTP traffic.
- The issue was triggered by changes to body parsing logic to mitigate a React Server Components vulnerability (CVE-2025-55182).
- A bug in the FL1 proxy's rules module caused HTTP 500 errors when a killswitch was applied to a rule with an 'execute' action.
- Customers using the older FL1 proxy with Cloudflare Managed Ruleset were affected; traffic in China was unaffected.
- Cloudflare plans to implement enhanced rollouts, streamlined break-glass capabilities, and 'fail-open' error handling to prevent future incidents.
- A detailed breakdown of resiliency projects will be published next week, with all network changes currently locked down.