According to the Grails project homepage version 3.3.4 is the latest release of Grails.
There are release notes for this release too but the refer to a GitHub milestone that contains no issues.
Does anyone know what in this latest release?
The only change appears to be in how request params are included when redirecting:
https://github.com/grails/grails-core/compare/v3.3.3...v3.3.4
Original params are no longer included when redirecting from a controller action.
It's odd that there was no issue linked for that though!
Summarizing for simplicity per comments below with Jeff: nothing is actually fixed in 3.3.4. There were changes to fix one particular issue but they did not work and will instead be included as a fix in 3.3.5.