Ubuntu 26.04 becomes a supported runner

GitHub has announced the general availability of its Ubuntu 26.04 runner image for GitHub Actions. The image is no longer in public preview and is now fully supported for production workflows running on both x64 and arm64 architectures.

The release gives workflow maintainers a new supported image option for projects that run automated builds, tests, or other GitHub Actions jobs. GitHub is presenting Ubuntu 26.04 as the latest supported Ubuntu release available through its hosted runner images.

New labels for explicit image selection

Teams that want to test or adopt the new image directly can update the runs-on setting in their workflow files. GitHub specifies runs-on: ubuntu-26.04 for the x64 image and runs-on: ubuntu-26.04-arm for the arm64 image.

Using an explicit label allows maintainers to test their workflows against Ubuntu 26.04 before the broader default migration begins. This is particularly relevant for workflows that depend on a particular preinstalled package, tool, or software version.

ubuntu-latest will move from Ubuntu 24.04

As part of the release, GitHub will migrate the ubuntu-latest label from Ubuntu 24.04 to Ubuntu 26.04. The change will not happen all at once: GitHub says the rollout will proceed gradually between October 19 and November 19, 2026.

During that window, workflows using ubuntu-latest will automatically begin running on the Ubuntu 26.04 image. Projects that use the moving label therefore may receive the new operating system image without a corresponding change to their workflow files.

Changed tools and package versions may affect builds

GitHub warns that Ubuntu 26.04 includes updated tools and tool versions, while some tools and versions from earlier images have been removed. Workflows built around specific software versions or preinstalled packages may therefore stop working after the image change.

The company recommends reviewing the complete list of differences and testing workflows against Ubuntu 26 before the migration starts. This preparation is intended to identify dependencies that are not available, have changed versions, or behave differently on the new runner image.

How maintainers can prepare

GitHub's primary recommendation is to test existing workflows with ubuntu-26.04 before the migration begins. Testing with the explicit image label gives teams an opportunity to find and correct build issues while their current default remains unchanged.

Projects that are not ready to move can instead pin their workflows to ubuntu-24.04. GitHub says this will keep those workflows on the current image rather than following the ubuntu-latest migration.

For further details, GitHub directs users to its documentation for GitHub-hosted runners. The company also points maintainers to the runner-images repository for the included software list and for reporting issues with the image.

Sources

• GitHub ChangelogUbuntu 26 generally available and latest migration