1. Customer created a ticket.
2. Agent replied to that ticket.
3. Customer replied via email including external vendor.
4. External vendor replied on that ticket.
5. Agent replied on the ticket.
6. Now, customer and external vendor both received email but if I check the recipients, in customer's inbox, the email (sent on step#5), external vendor's email address is missing.
Also, when checked external vendor's inbox, customer's email address as recipient is missing.
This is not expected behavior.
Now, after 5th step, if customer need to reply to the ticket, they will have to manually add external vendor while replying and vice-a-versa for external vendor.
Now when external participants received email, there is a link View Request. It redirect external user to JSM customer portal which is actually a customer's logged in session.
This is privacy/security critical issue. External vendor can change profile details. Although password change action seems challenging as external user would not know current password and if external user clicks on reset password, link email goes to customer.
But still this is breach of security.