Dear Qubes Community,
We're pleased to announce that the third release candidate (RC) for Qubes OS 4.3.0 is now available for testing. This minor release includes many new features and improvements over Qubes OS 4.2.
## What's new in Qubes 4.3?
- Dom0 upgraded to Fedora 41 ([#9402](Update dom0 to Fedora 41 · Issue #9402 · QubesOS/qubes-issues · GitHub)).
- Xen upgraded to version 4.19 ([#9420](Update Xen to 4.19 · Issue #9420 · QubesOS/qubes-issues · GitHub)).
- Default Fedora template upgraded to Fedora 42 (versions older than 41 not supported).
- Default Debian template upgraded to Debian 13 (versions older than 12 not supported).
- Default Whonix templates upgraded to Whonix 18 (upgraded from 17.4.3 in RC2; versions older than 18 no longer supported).
- Preloaded disposables ([#1512](Preloaded disposables · Issue #1512 · QubesOS/qubes-issues · GitHub))
- Device "self-identity oriented" assignment (a.k.a. New Devices API) ([#9325](Device "self-identity oriented" assignment · Issue #9325 · QubesOS/qubes-issues · GitHub))
- Qubes Windows Tools reintroduced with improved features ([#1861](qubes-windows-tools: Support for Windows 10/11 · Issue #1861 · QubesOS/qubes-issues · GitHub)).
These are just a few highlights from the many changes included in this release. For a more comprehensive list of changes, see the [Qubes OS 4.3 release notes](Qubes OS 4.3 release notes — Qubes OS Documentation).
## When is the stable release?
That depends on the number of bugs discovered in this RC and their severity. As explained in our [release schedule](Version scheme — Qubes OS Documentation) documentation, our usual process after issuing a new RC is to collect bug reports, triage the bugs, and fix them. If warranted, we then issue a new RC that includes the fixes and repeat the process. We continue this iterative procedure until we're left with an RC that's good enough to be declared the stable release. No one can predict, at the outset, how many iterations will be required (and hence how many RCs will be needed before a stable release), but we tend to get a clearer picture of this as testing progresses.
At this time, we expect that there will likely be a fourth release candidate, which will probably be the final one.
## How to test Qubes 4.3.0-rc3
Thanks to those who tested earlier 4.3 RCs and [reported bugs they encountered](Issue tracking — Qubes OS Documentation), 4.3.0-rc3 now includes fixes for several bugs that were present in those prior RCs!
If you'd like to help us [test](Testing new releases and updates — Qubes OS Documentation) this RC, you can [upgrade to Qubes 4.3.0-rc3](How to upgrade to Qubes 4.3 — Qubes OS Documentation) with either a clean installation or an in-place upgrade from Qubes 4.2. (Note for in-place upgrade testers: `qubes-dist-upgrade` now requires `--releasever=4.3` and may require `--enable-current-testing` for testing releases like this RC.) As always, we strongly recommend [making a full backup](How to back up, restore, and migrate — Qubes OS Documentation) beforehand and [updating Qubes OS](How to update — Qubes OS Documentation) immediately afterward in order to apply all available bug fixes.
If you're currently using an earlier 4.3 RC and wish to update to 4.3.0-rc3, please [update normally](How to update — Qubes OS Documentation) with [`current-testing` enabled](Testing new releases and updates — Qubes OS Documentation). If you use Whonix, please also [upgrade from Whonix 17 to 18](Release Upgrade Whonix 17 to Whonix 18).
Please help us improve the eventual stable release by [reporting any bugs you encounter](Issue tracking — Qubes OS Documentation). If you're an experienced user, we encourage you to [join the testing team](Joining the Testing Team).
## Known issues in Qubes OS 4.3.0-rc3
It is possible that templates restored in 4.3.0-rc3 from a pre-4.3 backup may continue to target their original Qubes OS release repos. This does not affect fresh templates on a clean 4.3.0-rc3 installation. For more information, see issue [#8701](Templates restored from backup created in older release silently continue to target old repos even after updating · Issue #8701 · QubesOS/qubes-issues · GitHub).
[View the full list of known bugs affecting Qubes 4.3](GitHub · Where software is built) in our [issue tracker](Issue tracking — Qubes OS Documentation).
## What's a release candidate?
A release candidate (RC) is a software build that has the potential to become a stable release, unless significant bugs are discovered in testing. RCs are intended for more advanced (or adventurous!) users who are comfortable testing early versions of software that are potentially buggier than stable releases. You can read more about Qubes OS [supported releases](Supported releases — Qubes OS Documentation) and the [version scheme](Version scheme — Qubes OS Documentation) in our documentation.
## What's a minor release?
The Qubes OS Project uses the [semantic versioning](https://semver.org/) standard. Version numbers are written as `[major].[minor].[patch]`. Hence, releases that increment the second value are known as "minor releases." Minor releases generally include new features, improvements, and bug fixes that are backward-compatible with earlier versions of the same major release. See our [supported releases](Supported releases — Qubes OS Documentation) for a comprehensive list of major and minor releases and our [version scheme](Version scheme — Qubes OS Documentation) documentation for more information about how Qubes OS releases are versioned.
This announcement is also available on the Qubes website: