Liberu CRM 0.9.1 < 10.0.0 Broken Access Control via TeamPolicy::addTeamMember()

Liberu CRM 0.9.1 before 10.0.0 contains a broken access control vulnerability that allows any user holding a pending team invitation to invite additional attacker-controlled accounts with elevated privileges by exploiting a flawed authorization predicate in TeamPolicy::addTeamMember() that grants invitation rights based solely on the existence of a pending invitation email match. Attackers can send a POST request to the team-invitations route specifying the admin role for a second account, bypassing privilege-level validation in InviteTeamMember, causing the second account upon invitation acceptance to be attached to the team with full admin-level create, read, update, and delete access over all team-scoped data.