It is a pleasure to inform that the new version of Lucene library and Solr search server has been released. It is another release from the 6.x branch and it is numbered 6.6.4. This release introduces critical security fixes found in Solr. We highly suggest upgrading your Solr instances.
Apache Lucene library 6.6.4 can be downloaded from http://www.apache.org/dyn/closer.cgi/lucene/java/. If you want to download Solr search server 6.6.4 go to http://www.apache.org/dyn/closer.cgi/lucene/solr/.