Grav API Plugin 1.0.9 Privilege Escalation via Invitations groups

Grav API Plugin versions before 1.0.10 fail to validate the groups field in InvitationsController::create(), allowing authenticated api.users.write callers to assign invited accounts to groups that grant api.super permissions. Attackers can create invitation records with elevated group membership, and when accepted, the new account gains full super-admin API access without the inviter holding those permissions.