Moderate Kernel Security Update for AlmaLinux: Addressing CVE-2025-39718 in Multiple Packages
Summary
ALSA-2025:21398: Moderate: kernel security update. Affects bpftool versions < 4.18.0-553.84.1.el8_10. Fixed in 4.18.0-553.84.1.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-grade Linux distribution, relies on a stable kernel to ensure system performance and security. This vulnerability affects various kernel-related packages, including bpftool, kernel, and kernel-debug, which are essential for system operation and performance tuning.
Vulnerability Detail
The vulnerability identified as CVE-2025-39718 pertains to the vsock/virtio subsystem of the Linux kernel. It arises from inadequate validation of packet header lengths before invoking the skb_put() function. This oversight can lead to potential memory corruption, allowing an attacker to exploit the system, potentially leading to unauthorized access or denial of service. The implications of this vulnerability are significant, as it can compromise the integrity and availability of the system.
How To Fix
Minimum fixed version
4.18.0-553.84.1.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, if updating is not immediately feasible, consider disabling the vsock/virtio functionality in your kernel configuration. This can mitigate the risk until a proper update can be applied. However, this may impact applications relying on this functionality.
Conclusion
The CVE-2025-39718 vulnerability presents a moderate risk to systems running affected versions of the Linux kernel and related packages in AlmaLinux. It is essential to apply the necessary updates to safeguard your system against potential exploits. Utilizing tools like Vulert can help monitor and manage vulnerabilities effectively.
See every vulnerability recorded for bpftool →
FAQ
CVE-2025-39718 is a vulnerability in the Linux kernel's vsock/virtio subsystem that allows for potential memory corruption due to improper validation of packet header lengths.
You can use the Vulert platform to check if your application is affected by this vulnerability. Simply upload your manifest file, such as package-lock.json, to monitor and alert for open-source vulnerabilities.
The risks include potential unauthorized access to the system, data breaches, and denial of service, which can severely impact system integrity and availability.
Yes, a patch is available in the form of kernel version 4.18.0-553.84.1.el8_10. Updating to this version will resolve the vulnerability.
If immediate updating is not possible, consider disabling the vsock/virtio functionality as a temporary workaround to mitigate risks.
Related vulnerabilities
Recent vulnerabilities recorded for bpftool.
