Elasticsearch has released versions 5.4.1 and 5.3.3, which include critical bug fixes and security patches, particularly for users of X-Pack Security. Version 5.4.1, based on Lucene 6.5.1, is the latest stable release and is available for deployment on Elastic Cloud. It addresses security issues such as a document level security bug with index aliases and a privilege escalation flaw in the run_as functionality. Users of X-Pack Security from versions 5.0.0 to 5.4.0 are advised to upgrade to these latest releases to mitigate these vulnerabilities. Additional improvements include addressing bugs related to single-shard scrolling, LDAP user caching, Netty resource allocation, and transport client sniffing protocol. The release also highlights enhancements in index setting validations and resolves issues with HDFS repository plugins and snapshot retrieval speeds. Users are encouraged to download the new versions, provide feedback, and report any issues on the GitHub page.