Create SECURITY.md

SECURITY.md

+# Security Policy
+
+## Supported Versions
+
+We actively support BigBlueButton through the community forums and through security updates.
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 2.0.x (or earlier)  | :x:                |
+| 2.2.x   | :white_check_mark: |
+| 2.3-dev   | :white_check_mark: |
+
+## Reporting a Vulnerability
+
+If you believe you have found a security vunerability in BigBlueButton please let us know directly by e-mailing security@bigbluebutton.org with as much detail as possible.
+
+Regards,... [BigBlueButton Team](https://docs.bigbluebutton.org/support/faq.html#bigbluebutton-committer)