MySQL NDB Cluster 8.0.15 was not released. NDB Cluster 8.0.14 is followed by NDB Cluster 8.0.16; users of NDB 8.0.14 should upgrade to 8.0.16 when the latter version becomes available.
Obtaining NDB Cluster 8.0. NDB Cluster 8.0 source code and binaries can be obtained from https://dev.mysql.com/downloads/cluster/.
For an overview of changes made in NDB Cluster 8.0, see What is New in MySQL NDB Cluster 8.0.