User can bypass approval when invited to Discourse

Discourse is an open source discussion platform. Versions prior to 2.7.13 in stable, 2.8.0.beta11 in beta, and 2.8.0.beta11 in tests-passed allow some users to log in to a community before they should be able to do so. A user invited via email to a forum with must_approve_users enabled is going to be automatically logged in, bypassing the check that does not allow unapproved users to sign in. They will be able to do everything an approved user can do. If they logout, they cannot log back in. This issue is patched in the stable version 2.7.13, beta version 2.8.0.beta11, and tests-passed version 2.8.0.beta11. One may disable invites as a workaround. Administrators can increase min_trust_level_to_allow_invite to reduce the attack surface to more trusted users.