https://arstechnica.com/security/20...-exposed-a-potpourri-of-secret-customer-data/ The bug was fixed within an hour, but probably best to be safe.
UPDATE: Work in Progress list of websites using cloudflare that may have been compromised. https://github.com/pirate/sites-using-cloudflare Some include Discord Humblebundle Patreon Reddit 4Chan Nexus Mods