To report a vulnerability you can create a new issue by clicking "new issue" in the issues tab and then clicking on "Report a security vulnerability".

All help and support to the project is greatly appreciated, so if there is something which seems off to you don't hesitate to tell me. When reporting an issue of whatever sort always remember to document it well as well as specify where in the code that issue is located, so that everyone browsing the issues tab will have greater chance of fixing it.