Ubuntu 25.10 daily builds are now running on the Linux 6.17 kernel.
Linux 6.17 isn’t released until late September, but the Canonical kernel team has changed its policy to always use the latest in-development kernel release in new Ubuntu version going forward, irrespective of whether its actually been released.
So, for the time being, Linux 6.17 is an “unstable” – a technical, not literal term – kernel snapshot based on a recent release candidate but with the usual Canonical patches, tuning and modifications applied on top of it.
Since the upstream Linux kernel release schedule and Ubuntu’s own development plans don’t align exactly (and kernel releases can slip) there had been uncertainty as to which kernel version would ship on the Ubuntu 25.10 ISO on release day: Linux 6.16 or a 6.17 RC.
Seems we have our answer; it’ll be Linux 6.17.
Depending on how soon Linux 6.17 arrives, it may well be an “unstable” snapshot pre-baked in the all-important Ubuntu 25.10 ISO which new installs boot from.
But as I said: it’s not literally unstable, and all users who install Ubuntu 25.10 with a potentially pre-stable version of Linux 617 will get a software update to the final stable version (the delta between the last RC and stable is usually negligible) once it’s available.
With lots of new features packed into the Linux 6.17 kernel, shipping the latest kernel on the ISO that users boot from is handy, especially for those trying the distro on newer hardware as support may/will have matured since the Linux 6.16 kernel release.
Something to look out for as we get closer to the Ubuntu 25.10 release date on 9 October, 2025.