Critical Security Update for Real Time Linux Kernel: kernel-rt Vulnerability
Summary
ALSA-2026:23259: Important: kernel-rt security update. Affects kernel-rt versions < 4.18.0-553.129.1.rt7.470.el8_10. Fixed in 4.18.0-553.129.1.rt7.470.el8_10. How to fix ↓
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Background
The kernel-rt package provides a Real Time Linux Kernel designed for systems that require high determinism and low latency. It is essential for applications in fields such as telecommunications, robotics, and industrial automation. The kernel-rt package allows for fine-tuning of system performance to meet stringent timing requirements, making it a critical component for real-time applications. However, vulnerabilities in this package can lead to severe security risks, potentially compromising system integrity and data security.
Vulnerability Detail
The vulnerability identified as CVE-2026-46243 affects the kernel-rt package, specifically in the SMB client functionality. This issue allows for the rejection of userspace cifs.spnego descriptions, which could lead to unauthorized access or denial of service. The vulnerability arises from improper handling of certain inputs, making it exploitable under specific conditions. If left unaddressed, it could result in significant security breaches, including data leaks and system instability.
How To Fix
Minimum fixed version
4.18.0-553.129.1.rt7.470.el8_10
This is the first release that contains the fix.
sudo dnf update kernel-rtTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users may consider disabling the SMB client functionality until the package can be updated. This can be done by modifying the configuration files related to SMB services, but it is recommended to apply the update as soon as possible to ensure system security.
Conclusion
The kernel-rt vulnerability CVE-2026-46243 poses a significant security risk to systems relying on the Real Time Linux Kernel. It is crucial for users to update their packages to the patched version to mitigate potential threats. Regular monitoring and updates are essential for maintaining system integrity and security.
See every vulnerability recorded for kernel-rt →
FAQ
CVE-2026-46243 is a security vulnerability in the kernel-rt package that affects the SMB client functionality, potentially allowing unauthorized access.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
Failing to update the kernel-rt package may expose your system to security breaches, including unauthorized access and data loss.
Yes, you can disable the SMB client functionality as a temporary workaround until the package is updated.
You can update the kernel-rt package by running 'sudo dnf update kernel-rt' in your terminal.
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