Security related - login as another user

Hello,
I've tested this in Chrome and replicated the behavior after seeing this happen initially. For security reasons I don't want to share publicly the entire vulnerability and steps to confirm - but would gladly discuss privately with support members.

The general idea is that after performing a couple steps as target user A , User B logs in and the website shows Users A name and Credentials as the person who has logged in. As User A , I can sign up for roles and edit A's profile, send out Agendas.

Let me know how to proceed.

Fellow Ambassadors,

I've got this one. I have contacted the member via Private Message.

I think we found the problem.