CVE-2018-10949
mailboxd in Zimbra Collaboration Suite 8.8 before 8.8.8; 8.7 before 8.7.11.Patch3; and 8.6 allows Account Enumeration by leveraging a Discrepancy between the "HTTP 404 – account is not active" and "HTTP 401 – must authenticate" errors.
Source: CVE-2018-10949