Introduction

These release notes for Kubuntu 25.10 (Questing Quokka) provide an overview of the release and document the known issues.

Support lifespan

Kubuntu 25.10 will be supported for 9 Months.

Getting Kubuntu 25.10

Upgrading from 25.04

Detailed upgrade instructions can be found here: https://help.ubuntu.com/community/QuestingUpgrades/Kubuntu

Download a Disk Image

Download a Bootable image. Direct downloads, torrents, and zysnc are available as options.

New features and changes in 25.10

Details of the changes in the Ubuntu base, including kernel, toolchain and build options can be found in the main Ubuntu Release Notes.

Kubuntu core desktop and applications

Plasma 6.4

The Kubuntu team have been working hard to ship 25.10 with the latest Qt6 based Plasma 6.4 KDE desktop.

Included is Plasma 6.4.5 which is the 5th and latest bugfix release of Plasma 6.4. New features in 6.4 can read here.

Plasma Wayland session

The Plasma Wayland session is the default.

Plasma X11 session

The Plasma X11 session is not installed by default on a clean install, but can be easily added by installing the plasma-session-x11 package.

Qt and KDE Frameworks

Kubuntu 25.10 ships with Qt6 6.9.2 and KDE Frameworks 6 version 6.17.0.

For applications that are still based on Qt5/KF5, Qt5 5.15.17 and Frameworks 5.116.0 are still in the archive.

KDE Applications updates

The majority of KDE gear are now at version 25.08.1.

Many other KDE applications have been updated.

Web browser and office suite

• Firefox 143 snap is the default browser from the Snap Store.

• LibreOffice 25.8 is provided by default in the full installation.

Kernel

Kubuntu 25.10 ships with the 6.17 Linux kernel.

Known issues

• flatpak is failing to install applications due to missing or incorrect apparmor rules in the profile for fusermount3. Please see 2122161 “error: Failed to install org.gnome.Platform: Could...” : Bugs : Release Notes for Ubuntu

• All bugs tagged with Kubuntu

Feedback

Development of Kubuntu 25.10, Questing Quokka, is ongoing and bugs are fixed every day. Before reporting bugs, please ensure your system is up to date. For verifying installation related bugs, updated disk images are available from Daily bootable images for standard PCs and laptops.

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