Security Update Released: CVE-2026-31431, CVE-2026-43284, CVE-2026-43500, CVE-2026-46333 - Linux Kernel Vulnerabilities

[jknorr]

We've released a patched RevPi kernel package for RevPi Bookworm and RevPi Bullseye that addresses the Linux kernel security vulnerabilities CVE-2026-31431 ("Copy Fail"), CVE-2026-46333 ("ssh-keysign-pwn") and CVE-2026-43284 ("Dirty Frag"). Our operating system is not affected by CVE-2026-43500. We recommend installing the update promptly.

How to Install the Update

You can find step-by-step instructions for updating your RevPis here in our documentation.

In the next few days we will also release a new RevPi Bookworm image containing the fixes. You will find it here.

If you've applied the immediate mitigation from our previous Update Tracker issue regarding CVE-2026-31431 (disabling algif_aead): If your setup requires the algif_aead kernel module, you can manually re-enable it after the update.

About The Vulnerabilities

AI-powered analysis is drastically accelerating the search for software vulnerabilities. The current focus is on the Linux kernel, as it serves as a central component in numerous modern devices. That security gaps are being identified and closed is all in all a positive development: every patch makes the system more secure. We will keep you up to date about further developments via our Update Tracker.

CVE-2026-31431 ("Copy Fail") is a privilege escalation vulnerability in the Linux kernel (introduced with version 4.14). It allows a local user – someone who already has access to the device – to gain root (administrator) privileges without authorization. The vulnerability is not remotely exploitable on its own, meaning an attacker needs local access to the device to exploit it.

CVE-2026-43284 and CVE-2026-43500 ("Dirty Frag") are vulnerabilities in the Linux kernel affecting ESP-in-UDP processing and DATA/RESPONSE packets, respectively. Our operating system is not affected by CVE-2026-43500.

CVE-2026-46333 ("ssh-keysign-pwn") is a vulnerability in the Linux kernel that allows unprivileged users to read files that are readable only by the root user.

Questions or Issues?

Feel free to write to us here in the forum. Would you like to be notified via email about our software updates? Subscribe to the RevPi Update Tracker.

Further Information

Linux announcements: CVE-2026-31431 / CVE-2026-43284 / CVE-2026-43500 / CVE-2026-46333
Debian kernel versions: CVE-2026-31431 / CVE-2026-43284 / CVE-2026-43500 / CVE-2026-46333
Possible exploitation: Copy Fail / Dirty Frag