Cloudflare outage caused by bad software deploy (updated)
This is a short placeholder blog and will be replaced with a full post-mortem and disclosure of what happened today.
For about 30 minutes today, visitors to Cloudflare sites received 502 errors caused by a massive spike in CPU utilization on our network. This CPU spike was caused by a bad software deploy that was rolled back. Once rolled back the service returned to normal operation and all domains using Cloudflare returned to normal traffic levels.
This was not an attack (as some have speculated) and we are incredibly sorry that this incident occurred. Internal teams are meeting as I write performing a full post-mortem to understand how this occurred and how we prevent this from ever occurring again.
Update at 2009 UTC:
Starting at 1342 UTC today we experienced a global outage across our network that resulted in visitors to Cloudflare-proxied domains being shown 502 errors (“Bad Gateway”). The cause of this outage was deployment of a single misconfigured rule within the Cloudflare Web Application Firewall (WAF) during a routine deployment of new Cloudflare WAF Managed rules.
The intent of these new rules was to improve the blocking of inline JavaScript that is used in attacks. These rules were Continue reading

