Wed, 3rd Jul 2019, 06:54
Wreck-It RegEx Breaks the Internet
https://blog.cloudflare.com/cloudflare-outage/

Cloudflare outage caused by bad software deploy (updated)
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)
blog.cloudflare.com