Critical Kernel Vulnerability in AlmaLinux: Important Update Required
Summary
ALSA-2026:36645: Important: kernel update. Affects kernel versions < 5.14.0-687.23.1.el9_8. Fixed in 5.14.0-687.23.1.el9_8. How to fix ↓
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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 system integrity and performance. Recent vulnerabilities have been identified in the kernel packages, necessitating immediate attention to maintain system security.
Vulnerability Detail
The vulnerabilities identified in the kernel packages include a use-after-free (UAF) issue in the eventpoll subsystem (CVE-2026-43074), a fix for ep_remove struct eventpoll and struct file UAF (CVE-2026-46242), and a netfilter-related vulnerability where the ebtables SNAT target writes to shared memory pages during ARP hardware address rewrite (CVE-2026-53266). These vulnerabilities could potentially allow an attacker to execute arbitrary code, leading to system compromise and unauthorized access.
How To Fix
Minimum fixed version
5.14.0-687.23.1.el9_8
This is the first release that contains the fix.
sudo dnf update kernelTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, users can limit access to the affected kernel features or disable the eventpoll subsystem until the update is applied. However, this may impact application performance and functionality.
Conclusion
The identified vulnerabilities in the AlmaLinux kernel packages pose significant security risks that require immediate attention. Updating to the patched version is critical to maintaining system integrity and protecting against potential exploits. Users are encouraged to utilize tools like Vulert for ongoing monitoring of vulnerabilities.
See every vulnerability recorded for kernel →
FAQ
CVE-2026-43074 is a vulnerability in the Linux kernel's eventpoll subsystem that allows for a use-after-free condition, potentially leading to arbitrary code execution.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit Vulert Scanner to check if your application is affected by this vulnerability.
Failing to update the kernel exposes your system to potential exploits that can lead to unauthorized access, data breaches, and system instability.
While the best course of action is to update, you can temporarily limit access to the affected kernel features or disable the eventpoll subsystem.
If you experience problems after updating, consider rolling back to the previous kernel version or consulting the AlmaLinux community for support.
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