From the post:
Today Apache Lucene and Solr PMC announced a new of Apache Lucene library and Apache Solr search server – the 4.7 one. This is another release from the 4.x brach bringing new functionalities and bugfixes.
Apache Lucene 4.7 library can be downloaded from the following address: http://www.apache.org/dyn/closer.cgi/lucene/java/. Apache Solr 4.7 can be downloaded at the following URL address: http://www.apache.org/dyn/closer.cgi/lucene/solr/. Release note for Apache Lucene 4.7 can be found at: http://wiki.apache.org/lucene-java/ReleaseNote47, Solr release notes can be found at: http://wiki.apache.org/solr/ReleaseNote47.
Time to upgrade, again!