USN-8920-1: Linux kernel flaws in AWS, Azure and IBM on Ubuntu
Canonical fixes a dozen CVEs in the cloud kernel on Ubuntu 18.04 and 20.04: reboot required and patches available only with Ubuntu Pro.
UptimeMag editorial team · 13 October 2026 · 1 min read
Canonical released security advisory USN-8920-1 on 13 October 2026, patching a dozen vulnerabilities in the Linux kernel used by Ubuntu 18.04 LTS (bionic) and 20.04 LTS (focal) cloud images. The affected packages are linux-aws-5.4, linux-aws-fips, linux-azure-fips, linux-ibm and linux-ibm-5.4: anyone running VPS or instances on Amazon Web Services, Microsoft Azure or IBM Cloud with these two releases should check for the update.
The flaws affect multiple kernel subsystems: Ethernet bonding driver, network drivers, F2FS filesystem, NFS server daemon, tracing infrastructure, io_uring subsystem, networking core, IPv6 stack, IUCV driver, Netfilter and RxRPC session sockets. The security advisory lists twelve CVEs, including CVE-2026-53221, CVE-2026-53131, CVE-2026-52910, CVE-2026-43456 and CVE-2025-38724, along with several CVEs from 2024 and 2022 still undergoing backporting.
Mandatory reboot and kernel module recompilation
As seen in previous kernel advisories, this update introduces an ABI change: the kernel version number changes, so after the update the machine must be rebooted and all manually installed third-party kernel modules must be recompiled and reinstalled. Users who have not modified the standard metapackages (linux-generic, linux-virtual and similar) need not worry: the operation happens automatically during the upgrade.
Ubuntu Pro required
For all listed packages, on both 18.04 and 20.04, the advisory states "Fix available with Ubuntu Pro": without an active subscription, the patch will not be delivered. The good news is that Ubuntu Pro remains free for up to five machines for personal use; for commercial use the official pricing indicates £20 per year for workstations and £400 per year for servers, rising to £2,700 with full 24/7 support.
| Release | Package | Version |
|---|---|---|
| 20.04 LTS | linux-image-5.4.0-1111-ibm | 5.4.0-1111.116 |
| 20.04 LTS | linux-image-5.4.0-1165-aws-fips | 5.4.0-1165.176+fips1 |
| 20.04 LTS | linux-image-5.4.0-1170-azure-fips | 5.4.0-1170.176+fips1 |
| 18.04 LTS | linux-image-5.4.0-1111-ibm | 5.4.0-1111.116~18.04.1 |
| 18.04 LTS | linux-image-5.4.0-1165-aws | 5.4.0-1165.176~18.04.1 |
The full advisory text, with the complete list of all packages and the twelve CVEs, is available on the official page ubuntu.com/security/notices/USN-8920-1.
Written with the help of artificial intelligence and checked by the editors (EU AI Act, art. 50).