By now you may have heard about “Cloudbleed”, the recently discovered vulnerability affecting users of Cloudflare’s SSL proxy service. In short, websites that utilized the service were affected by a serious issue that resulted in sensitive data (including passwords, API keys, private information, etc.) being leaked. Some of this data was inadvertently cached by search engines and potentially intentionally gathered by “bad guys”.
phpBB.com does not utilize the Cloudflare SSL proxy service and is thus unaffected.
Having said that, hundreds of websites you do use were affected, and you should take this opportunity to reset your passwords, regenerate API keys, etc., especially on services of importance.
CloudFlare’s official post about the matter can be found on the CloudFlare Blog
For an incomplete list of possibly affected websites and a great deal more information about this, you can look here: https://github.com/pirate/sites-using-cloudflare