More like:
"Dear Grabastic,
Today we had a demonstration by a user (xxx) of a security vulnerability on our site.
${VULNERABILITY_EXPLANATION}
We believe that it is possible that your application or records are covered in the scope of the exploit, because of the fact that ${VULNERABILITY_APPLICATION}.
In order to fix this issue, we have ${VULNERABILITY_PATCH}.
We have thanked this user for their vigilance in spotting bugs and security weaknesses in our site, and they have been added to our contributors-security page here (link).
We have a stance that security is something that can only be improved by lots of inquisitive eyes, and so if you have seen any issues that concern you, please do not hesitate to inform us and/or demonstrate the vulnerability--provided, of course, you do so without breaking anything permanently. :)
Our service is better today than it was yesterday, and we hope that with the patience and openness of our users it will be still better tommorrow!
Sincerely,
angersock
"
See, not so hard!