There are two versions of the LDAP library in OpenLDAP: libldap and libldap_r. libldap_r is apparently a threadsafe version of libldap.

Other downstream distributions such as Debian symlink libldap to libldap_r. RHEL 7 does not, thus MongoDB Enterprise can have multiple threads using libldap with the potential for race conditions.

To work around this issue, one can manually symlink libldap to libldap_r as needed.