Moderate Kernel Security Update for AlmaLinux: Addressing Vulnerabilities in Multiple Packages
Summary
ALSA-2026:3963: Moderate: kernel security update. Affects bpftool versions < 4.18.0-553.111.1.el8_10. Fixed in 4.18.0-553.111.1.el8_10. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Habilume
Habit tracker with a companion that grows with you
Complete habits, earn Lume Points, and watch your Lume grow as you stay consistent.
Background
The kernel is the core component of any Linux operating system, responsible for managing system resources and facilitating communication between hardware and software. AlmaLinux, a community-driven enterprise-grade Linux distribution, relies on a stable and secure kernel to ensure optimal performance and security. The recent vulnerabilities identified in the kernel packages, including bpftool and various kernel modules, pose significant risks that could compromise system integrity and security.
Vulnerability Detail
The vulnerabilities stem from two primary issues: a bug in the IPv6 implementation leading to a potential crash in the pskb_expand_head() function (CVE-2025-71085) and a use-after-free (UAF) condition in the macvlan_forward_source() function (CVE-2026-23001). These vulnerabilities could allow an attacker to exploit the kernel, potentially leading to system crashes, unauthorized access, or data corruption.
How To Fix
Minimum fixed version
4.18.0-553.111.1.el8_10
This is the first release that contains the fix.
sudo dnf update bpftoolTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, users may consider disabling IPv6 or avoiding the use of macvlan networking until the system can be updated. However, this is not a permanent solution and should only be used until the patch is applied.
Conclusion
In summary, the recent kernel vulnerabilities in AlmaLinux pose significant risks that need to be addressed promptly. Users are encouraged to update their systems to the latest patched versions to mitigate these vulnerabilities effectively. Utilizing tools like Vulert can help monitor and manage vulnerabilities in real-time.
See every vulnerability recorded for bpftool →
FAQ
The vulnerabilities could lead to system crashes, unauthorized access, or data corruption, posing significant risks to system integrity.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without any signup.
If immediate updates are not possible, consider disabling IPv6 or avoiding the use of macvlan networking as a temporary workaround.
Regularly check for updates and vulnerabilities, ideally on a weekly basis, to ensure your system remains secure.
Vulert is a tool that monitors and alerts in real-time for open-source vulnerabilities in software, using just a manifest file like package-lock.json.
Related vulnerabilities
Recent vulnerabilities recorded for bpftool.
Habilume
Habit tracker with a companion that grows with you
Complete habits, earn Lume Points, and watch your Lume grow as you stay consistent.
