Ubuntu 22.04 affected by CVE-2026-31431? — Has 22.04 received the fix?

Support and Help
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· OS: Ubuntu 20.04.6 LTS Server

· Current kernel: 5.4.0-XX-generic(I didn’t see the specific kernel version)

· Architecture: x86_64

I’m looking into CVE-2026-31431 (“Copy Fail”), a local privilege escalation vulnerability. According to public information, it affects almost all Linux distributions from 2017 onward. A local user with a shell can exploit the AF_ALG interface combined with splice() to corrupt page cache of setuid binaries, gaining root privileges. No race condition required, and a PoC has been publicly released.

Questions

1. Regarding the 5.15 HWE kernel: If I install linux-generic-hwe-20.04 to upgrade to the 5.15 HWE kernel, does that version still have CVE-2026-31431?

2. Regarding Livepatch: Has Canonical Livepatch released a hot fix for CVE-2026-31431 yet? If yes, which kernel versions are covered?

3. Regarding Ubuntu 22.04: Has Ubuntu 22.04 LTS already received the kernel patch for this vulnerability?

Thanks

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For our public:

The fix saga begins here:
https://lists.ubuntu.com/archives/kernel-team/2026-April/167446.html

-Security Team on top-

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I’ll refer you to the Support and Help start here page, where it clearly states and shows that only releases in standard support are on-topic here.

Your post does include some parts that do relate to on-topic releases (ie. 22.04), so I’ll edit your question and strikeout the off-topic components.

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We’ve taken to adding the boot option
initcall_blacklist=algif_aead_init

The github check script then shows the server as safe

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