CloudBleed is a new vulnerability that effects CloudFlare. CloudFare is a content delivery network and security provided that is the backbone of some very large, big name websites. This new vulnerability has made it possible for sensitive information; passwords, encrypted keys, and more. A simple Google search will not bring up this leaked information. As with any security breach, the standard protocol is to change your password immediately. The leak has bee patched but it has affected quite a few websites
See the extension for chrome and firefox: http://www.addictivetips.com/web/how-to-check-if-a-website-is-affected-by-cloudbleed/ (probably a script blocker like NoScript or uMatrix might have mitigated the threat when it was still there). It is always a good policy to regularly change your account passwords, whenever you were on affected websites or as a general precaution matter against private data breaches. A remote risk, let us call it that, but always better safe than sorry. I reported it here just for awareness to the fact it was around.