Call for testing — patched kernels for Copy Fail (CVE-2026-31431)
Hello AlmaLinux Users, A few days ago Xint Code disclosed Copy Fail (CVE-2026-31431), a Linux kernel logic flaw in the crypto subsystem (algif_aead chained through AF_ALG and splice()). It lets any unprivileged local user escalate to root with a 732-byte exploit that the researchers report is 100% reliable across every mainstream Linux distribution built since 2017. Every supported AlmaLinux release is affected. Red Hat has not yet shipped a kernel update, so our core team has built patched kernels for AlmaLinux 8, 9, 10, and Kitten 10 using the upstream fix. ALESCo approved shipping ahead of upstream — the patched kernels are in the testing repository today, and they'll move to production once the community has helped us verify them. If you can spare a test box — especially anything multi-tenant, a container host, or a CI runner where untrusted users get a shell — we'd love your help testing. Full instructions, kernel versions, and feedback channels are on the blog: https://almalinux.org/blog/2026-05-01-cve-2026-31431-copy-fail/ -- Jonathan Wright AlmaLinux OS Foundation Mattermost: chat <https://chat.almalinux.org/almalinux/messages/@jonathan>
As a followup tothe call for testing earlier, the patches are now published to production repositories and are syncing out to mirrors. The blog post has been updated accordingly. Thanks everyone for the help with testing! https://almalinux.org/blog/2026-05-01-cve-2026-31431-copy-fail/ On Fri, May 1, 2026 at 9:37 AM Jonathan Wright <jonathan@almalinux.org> wrote:
Hello AlmaLinux Users,
A few days ago Xint Code disclosed Copy Fail (CVE-2026-31431), a Linux kernel logic flaw in the crypto subsystem (algif_aead chained through AF_ALG and splice()). It lets any unprivileged local user escalate to root with a 732-byte exploit that the researchers report is 100% reliable across every mainstream Linux distribution built since 2017.
Every supported AlmaLinux release is affected. Red Hat has not yet shipped a kernel update, so our core team has built patched kernels for AlmaLinux 8, 9, 10, and Kitten 10 using the upstream fix. ALESCo approved shipping ahead of upstream — the patched kernels are in the testing repository today, and they'll move to production once the community has helped us verify them.
If you can spare a test box — especially anything multi-tenant, a container host, or a CI runner where untrusted users get a shell — we'd love your help testing. Full instructions, kernel versions, and feedback channels are on the blog:
https://almalinux.org/blog/2026-05-01-cve-2026-31431-copy-fail/
-- Jonathan Wright AlmaLinux OS Foundation Mattermost: chat <https://chat.almalinux.org/almalinux/messages/@jonathan>
-- Jonathan Wright AlmaLinux OS Foundation Mattermost: chat <https://chat.almalinux.org/almalinux/messages/@jonathan>
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Jonathan Wright