Elasticsearch 5.2.1, based on Lucene 6.4.1, has been released and is now available for deployment on Elastic Cloud, with users encouraged to upgrade. This release includes mostly minor bug fixes, but importantly addresses two significant memory leaks in Lucene: one related to the use of Deflater/Inflater instances with best_compression, which was causing issues with native memory usage, and another concerning cached queries retaining references to IndexReader, preventing timely segment deletion. Users are invited to download the new version, provide feedback via Twitter or forums, and report any issues on GitHub.