Logstash versions 2.3.1 and 2.2.4 have been released, providing significant compatibility and security updates, and users are encouraged to upgrade immediately. The Logstash 2.3.1 release addresses several issues, including a regression in regex handling due to an upgraded JRuby version, which introduced a thread safety bug. Environment variable support was added in 2.3.0 but is now disabled by default in 2.3.1 due to compatibility problems with existing configurations, though it can be enabled via a command-line flag. The new Java implementation of the Event class was reverted to the previous Ruby version due to compatibility issues, but the Java version is expected to return in future releases. Additionally, Logstash 2.3.1 fixes a bug where plaintext passwords were printed in log files under certain conditions and resolves a broken configuration test flag from the 2.3.0 release. Users are invited to provide feedback on the release through various channels.