We have an (empty) repo on GitHub specifically for bug tracking. If you'd like to track your bug publicly, feel free to file an issue over there.
If you'd like to talk with us over email, use this form.
We have lots of information available in our documentation that might help you with your issue.
We track security concerns through BugCrowd. Please submit security problems there. We hugely appreciate that. Plus this way you get public credit for your work.
We prefer you use the form, because it helps us know a bit more about you and your account. But if that form isn't working or you really prefer email, you can reach us at [email protected]