We just published the fourth release candidate for the next major version 1.7 of Roundcube webmail.
This release fixes two minor issues, it's mostly published to fix a file permission problem in the previous release v1.7-rc3.
The changes are:
The tarballs can be downloaded from roundcube.net/download.
Or directly from the release page at github.com.
We believe it is production ready, but we recommend to test it on a separate environment.
Migrate existing configs with either the installto.sh or the update.sh scripts.
And don't forget to backup your data before installing it!
Regards, Pablo