We just packaged the RC 1 version of all maintenance releases that are planned for the next week. As always you can either download them directly from prerelease folder on the download server: https://download.nextcloud.com/server/prereleases/ or you use the beta channel of the built-in updater and use that.
As always: have an backup available and keep rocking
The changelog of those releases can be found here:
If you find bugs report them in our bug tracker: https://github.com/nextcloud/server/issues and if it is a bug that is related to the update itself you can get at least a Nextcloud t-shirt. (@jospoortvliet knows more on this one)