Ubuntu USN · USN-8255-2

Linux kernel (Azure) vulnerabilities

Published: Mon, 11 May 2026 14:02

CVE-2026-23273CVE-2023-2640CVE-2026-23112CVE-2023-32629

Summary

Several security issues were fixed in the Linux kernel.

Details

Stonejiajia, Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in the Ubuntu Linux kernel did not properly perform permission checks in certain situations. A local attacker could possibly use this to gain elevated privileges. (CVE-2023-2640) Shir Tamari and Sagi Tzadik discovered that the OverlayFS implementation in the Ubuntu Linux kernel did not properly perform permission checks in certain situations. A local attacker could possibly use this to gain elevated privileges. (CVE-2023-32629) Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - Network drivers; - NVME drivers; (CVE-2026-23112, CVE-2026-23273)

Recommended actions per Ubuntu release

StackPatch playbook auto-generated per release codename and per affected package.

Ubuntu focal

linux-azure-5.15→5.15.0-1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0-1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure-5.15
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-azure→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-azure-5.15→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure-5.15
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-azure-5.15-cloud-tools-5.15.0-1111→5.15.0-1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0-1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure-5.15-cloud-tools-5.15.0-1111
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-azure-5.15-headers-5.15.0-1111→5.15.0-1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0-1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure-5.15-headers-5.15.0-1111
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-azure-5.15-tools-5.15.0-1111→5.15.0-1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0-1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure-5.15-tools-5.15.0-1111
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-azure-cvm→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure-cvm
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-azure-edge→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-azure-edge
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-buildinfo-5.15.0-1111-azure→5.15.0-1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0-1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-buildinfo-5.15.0-1111-azure
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-cloud-tools-5.15.0-1111-azure→5.15.0-1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0-1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-cloud-tools-5.15.0-1111-azure
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-cloud-tools-azure→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-cloud-tools-azure
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-cloud-tools-azure-5.15→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-cloud-tools-azure-5.15
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-cloud-tools-azure-cvm→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-cloud-tools-azure-cvm
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-cloud-tools-azure-edge→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-cloud-tools-azure-edge
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-headers-5.15.0-1111-azure→5.15.0-1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-headers-5.15.0-1111-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-headers-azure→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-headers-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-headers-azure-5.15→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-headers-azure-5.15
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-headers-azure-cvm→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-headers-azure-cvm
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-headers-azure-edge→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-headers-azure-edge
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-image-5.15.0-1111-azure→5.15.0-1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-image-5.15.0-1111-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-image-azure→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-image-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-image-azure-5.15→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-image-azure-5.15
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-image-azure-cvm→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-image-azure-cvm
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-image-azure-edge→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-image-azure-edge
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-image-unsigned-5.15.0-1111-azure→5.15.0-1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-image-unsigned-5.15.0-1111-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-5.15.0-1111-azure→5.15.0-1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-5.15.0-1111-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-extra-5.15.0-1111-azure→5.15.0-1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-extra-5.15.0-1111-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-extra-azure→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-extra-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-extra-azure-5.15→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-extra-azure-5.15
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-extra-azure-cvm→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-extra-azure-cvm
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-extra-azure-edge→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-extra-azure-edge
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-involflt-5.15.0-1111-azure→5.15.0-1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-involflt-5.15.0-1111-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-involflt-azure→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-involflt-azure
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-involflt-azure-5.15→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-involflt-azure-5.15
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-involflt-azure-cvm→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-involflt-azure-cvm
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-modules-involflt-azure-edge→5.15.0.1111.120~20.04.1kernel_reboot
Kernel package — apt-upgrade then REBOOT to load the patched kernel.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-modules-involflt-azure-edge
sudo reboot
```
Reboot is required. ~30-60s downtime; containers self-restart.
linux-tools-5.15.0-1111-azure→5.15.0-1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0-1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-tools-5.15.0-1111-azure
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-tools-azure→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-tools-azure
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-tools-azure-5.15→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-tools-azure-5.15
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-tools-azure-cvm→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-tools-azure-cvm
```
Most apt upgrades restart their service automatically. needrestart lists anything else.
linux-tools-azure-edge→5.15.0.1111.120~20.04.1apt_upgrade
Standard apt upgrade. Install 5.15.0.1111.120~20.04.1 from the apt repo.
```
sudo apt-get update
sudo apt-get install --only-upgrade -y linux-tools-azure-edge
```
Most apt upgrades restart their service automatically. needrestart lists anything else.

Are YOU affected by USN-8255-2?

5-second check on your actual server. Reads /etc/os-release, uname -r, and dpkg-query; matches against the live USN + Debian Security Tracker feeds; tells you whether USN-8255-2 (and any other live CVE) applies. Anonymous, no signup.

curl https://mindsparkstack.com/scan.sh | bash

Form-based quickscan Read the bash source first

Want this automated for your servers?

StackPatch runs this match against YOUR installed packages every hour

Free 1-server / $99 lifetime founder seat (50 only) / $19+/mo monthly. Indie pricing.

Buy lifetime →See StackPatch →Live audit log →