Critical Security Update for Real Time Linux Kernel: kernel-rt Vulnerability
Summary
ALSA-2026:39180: Important: kernel-rt security update. Affects kernel-rt versions < 4.18.0-553.144.1.rt7.485.el8_10. Fixed in 4.18.0-553.144.1.rt7.485.el8_10. How to fix ↓
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Background
The kernel-rt package provides a Real Time Linux Kernel designed for systems requiring high determinism. It is essential for applications where timing is critical, such as in industrial automation and real-time data processing. This package allows for fine-tuning of system performance to meet stringent timing requirements. However, vulnerabilities in the kernel can lead to severe security risks, affecting system stability and data integrity.
Vulnerability Detail
The vulnerability arises from issues in the kernel-rt packages, specifically related to the handling of network bridge forwarding database (FDB) entries and the management of xfrm_state lists. The first issue (CVE-2026-46086) involves using a stable FDB destination snapshot in RCU readers, which could potentially allow an attacker to manipulate network traffic. The second issue (CVE-2026-46116) pertains to the defensive unhashing of xfrm_state lists during deletion, which could lead to data corruption or system crashes. Additionally, there is a risk of XFS data corruption when using reflink, which can compromise data integrity.
How To Fix
Minimum fixed version
4.18.0-553.144.1.rt7.485.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 measure, if immediate updating is not possible, consider disabling the affected features related to network bridging and xfrm states until the update can be applied. This can help mitigate the risk of exploitation while maintaining system functionality.
Conclusion
The kernel-rt vulnerability poses significant risks to systems relying on Real Time Linux Kernel for critical applications. Immediate action is required to update to the patched version to mitigate these risks. Regular monitoring and updates are essential for maintaining system security.
See every vulnerability recorded for kernel-rt →
FAQ
The kernel-rt package provides a Real Time Linux Kernel optimized for applications requiring high determinism and precise timing.
Exploitation of this vulnerability could lead to data corruption, system crashes, or unauthorized manipulation of network traffic.
You can use the Vulert platform to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check your application without needing to sign up.
If you cannot update the kernel-rt packages right away, consider disabling the affected features related to network bridging and xfrm states as a temporary workaround.
It is recommended to regularly check for vulnerabilities, especially after updates or changes to your system, to ensure ongoing security.
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