Support of the Rails framework is divided into four groups: New features, bug fixes, security issues, and severe security issues. They are handled as follows, all versions in X.Y.Z format.
New features are only added to the master branch and will not be made available in patch releases.
Only the latest release series will receive bug fixes. When enough bugs are fixed and its deemed worthy to release a new gem, this is the branch it happens from.
In special situations, where someone from the Rails core team agrees to support more series, they are included in the list of supported series.
Currently included series: 5.1.Z.
See the security policy for more details.
When a release series is no longer supported, it's your own responsibility to deal with bugs and security issues. We may provide backports of the fixes and publish them to git, however there will be no new versions released. If you are not comfortable maintaining your own versions, you should upgrade to a supported version.