Critical Kernel Security Update for AlmaLinux: Addressing Multiple Vulnerabilities
Summary
ALSA-2026:45115: Important: kernel security update. Affects bpftool versions < 4.18.0-553.147.1.el8_10. Fixed in 4.18.0-553.147.1.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
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 Linux distribution, relies on a stable and secure kernel to ensure optimal performance and security. The recent vulnerabilities identified in the kernel packages could potentially compromise system integrity and expose sensitive data.
Vulnerability Detail
The vulnerabilities stem from various issues within the kernel, including improper handling of user-space I/O in KVM (CVE-2025-40026), inadequate limits on xfrm single-frag length, an out-of-bounds write due to region_count overflow (CVE-2026-53059), and a double-free error in tipc_buf_append() (CVE-2026-52993). These vulnerabilities could lead to unauthorized access, data corruption, or system crashes, posing significant risks to system security and stability.
How To Fix
Minimum fixed version
4.18.0-553.147.1.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 can limit access to sensitive system components and monitor system logs for unusual activity. However, the most effective solution is to apply the kernel update as soon as possible.
Conclusion
The kernel vulnerabilities identified in AlmaLinux pose significant risks to system security and stability. It is crucial for users to apply the recommended updates promptly to safeguard their systems against potential exploits. Utilizing tools like Vulert can further enhance security by providing real-time monitoring of vulnerabilities.
See every vulnerability recorded for bpftool →
FAQ
The update addresses multiple vulnerabilities, including improper handling of user-space I/O, inadequate limits on xfrm single-frag length, out-of-bounds write issues, and double-free errors.
You can use Vulert, which monitors and alerts for open-source vulnerabilities in real-time. By using the Vulert playground, you can check if your application is affected without needing to sign up.
If immediate updates are not possible, limit access to sensitive components and monitor system activity closely until the update can be applied.
Generally, kernel updates are designed to maintain compatibility with existing applications. However, it is advisable to test critical applications after the update.
Detailed information can be found in the advisory linked in the vulnerability report, as well as on security-focused websites and forums.
Related vulnerabilities
Recent vulnerabilities recorded for bpftool.
