[qubes-users] Qubes OS 4.2.1 has been released!

Dear Qubes Community,

We're pleased to announce the stable release of Qubes OS 4.2.1! This [patch release](#what-is-a-patch-release) aims to consolidate all the security patches, bug fixes, and other updates that have occurred since the release of Qubes 4.2.0. Our goal is to provide a secure and convenient way for users to install (or reinstall) the latest stable Qubes release with an up-to-date ISO. The ISO and associated [verification files](Verifying signatures | Qubes OS) are available on the [downloads](Download Qubes OS | Qubes OS) page.

## What's new in Qubes OS 4.2.1?

Qubes 4.2.1 includes numerous updates over the initial 4.2.0 release, in particular:

- All 4.2 dom0 updates to date
- Fedora 39 template
- Linux 6.6.x as the default kernel, significantly reducing the need for `kernel-latest` on newer systems

For more information about the changes included in this version, see the [full list of issues completed since the release of 4.2.0](Issues · QubesOS/qubes-issues · GitHub).

## How to get Qubes OS 4.2.1

You have a few different options, depending on your situation:

- If you'd like to install Qubes OS for the first time or perform a clean reinstallation on an existing system, there's never been a better time to do so! Simply [download](Download Qubes OS | Qubes OS) the Qubes 4.2.1 ISO and follow our [installation guide](Installation guide | Qubes OS).

- If you're currently on Qubes 4.1, learn [how to upgrade to Qubes 4.2](How to upgrade to Qubes 4.2 | Qubes OS).

- If you're currently on Qubes 4.2 (including 4.2.0 and 4.2.1-rc1), [update normally](How to update | Qubes OS) (which includes [upgrading any EOL templates](How to update | Qubes OS) you might have) in order to make your system essentially equivalent to the stable Qubes 4.2.1 release. No reinstallation or other special action is required.

In all cases, we strongly recommend [making a full backup](How to back up, restore, and migrate | Qubes OS) beforehand.

## Reminder: new signing key for Qubes OS 4.2

As a reminder, we published the following special announcement in [Qubes Canary 032](Qubes Canary 032 | Qubes OS) on 2022-09-14:

We plan to create a new Release Signing Key (RSK) for Qubes OS 4.2. Normally, we have only one RSK for each major release. However, for the 4.2 release, we will be using Qubes Builder version 2, which is a complete rewrite of the Qubes Builder. Out of an abundance of caution, we would like to isolate the build processes of the current stable 4.1 release and the upcoming 4.2 release from each other at the cryptographic level in order to minimize the risk of a vulnerability in one affecting the other. We are including this notice as a canary special announcement since introducing a new RSK for a minor release is an exception to our usual RSK management policy.

As always, we encourage you to [authenticate](Qubes security pack (qubes-secpack) | Qubes OS) this canary by [verifying its PGP signatures](Verifying signatures | Qubes OS). Specific instructions are also included in the [canary announcement](Qubes Canary 032 | Qubes OS).

As with all Qubes signing keys, we also encourage you to [authenticate](Verifying signatures | Qubes OS) the new Qubes OS Release 4.2 Signing Key, which is available in the [Qubes Security Pack (qubes-secpack)](Qubes security pack (qubes-secpack) | Qubes OS) as well as on the [downloads](Download Qubes OS | Qubes OS) page.

## What is a patch release?

The Qubes OS Project uses the [semantic versioning](https://semver.org/) standard. Version numbers are written as `<major>.<minor>.<patch>`. Hence, we refer to releases that increment the third number as "patch releases." A patch release does not designate a separate, new major or minor release of Qubes OS. Rather, it designates its respective major or minor release (in this case, 4.2) inclusive of all updates up to a certain point. (See [supported releases](Supported releases | Qubes OS) for a comprehensive list of major and minor releases.) Installing the initial Qubes 4.2.0 release and fully [updating](How to update | Qubes OS) it results in essentially the same system as installing Qubes 4.2.1. You can learn more about how Qubes release versioning works in the [version scheme](Version scheme | Qubes OS) documentation.

This announcement is also available on the Qubes website:


It would be much better to have a more detailed (yet concise)
changelog. It is highly unlikely that the user will read pages upon
pages of issues on a bug tracker, just to find out what is new.

My $0.02. :slight_smile:


The concise changelog is already present, in the part you elided. Unlike major and minor releases, the primary purpose of patch releases is not to deliver new features or enhancements worth showcasing. Rather, the primary purpose is to provide a secure and convenient way for users to install (or reinstall) the latest stable Qubes release with an up-to-date ISO.

Imagine if we had a major or minor release, then we didn't have any further releases for a year. Users who wanted to (re)install Qubes would have to use a year-old ISO, then immediately catch up on a year's worth of updates, which could take quite a long time. Moreover, any bugs that affected the installation or initial update processes themselves might be complete blockers for some users. A security vulnerability in the update mechanism could make that initial update risky.

The purpose of these patch releases is mainly just to move up the "starting point" so that fresh installations don't have as far to "catch up" before they're on par with existing, regularly-updated installations. That's why the main summary of changes is just "all the routine updates you would've gotten if you had installed 4.2.0 and kept it up to date." Some of these routine updates will be of interest to some users while being of no interest at all to most other users. There should rarely be any that are of interest to *all* users. (Those should usually go in major or minor releases instead.)

1 Like

Thanks for explaining.

With the obvious exception of security patches.
- --
Demi Marie Obenour (she/her/hers)
Invisible Things Lab

1 Like

It occurred to me after I sent this that someone would probably point this out. Yes, but we already make a separate announcement for each and every QSB, so it would be somewhat redundant to repeat that in every patch release announcement. I'm not sure why listing the exact QSB patches included in a given patch release would be more useful to the average user than just saying "includes all security patches to date" (which is entailed by "includes all updates to date").

Targeting abstract entities is confusing.

Feel free to replace that part with "to the vast majority of users," then.