CVE-2026-74516 Linux CVE debrief

Who should care

Defenders responsible for Linux kernel and KVM deployments should assess exposure and prioritize patching affected versions. This includes operators managing Linux-based systems, platform administrators overseeing KVM environments, vulnerability management teams evaluating the impact of this vulnerability, and security teams responsible for ensuring the security of Linux kernel and KVM deployments.

Why it matters

This vulnerability in the Linux kernel's KVM subsystem could allow a guest to cause a denial of service (DoS) to the host system. Defenders responsible for Linux kernel and KVM deployments should assess exposure and prioritize patching affected versions. The vulnerability requires verification of AVIC configuration and potential updates to x2APIC MSR intercepts.

• Potential denial of service (DoS) to the host system
• Need for verification and patching of affected Linux kernel versions
• Importance of proper AVIC configuration in KVM setups

Technical summary

The Linux kernel's KVM subsystem, specifically the SVM component, has a vulnerability related to updating x2APIC MSR intercepts when AVIC is inhibited while L2 is active. This issue could allow a guest to trivially DoS the host by sending arbitrary interrupts, changing task priority, or reading most of the host's APIC state. The vulnerability requires verification of AVIC configuration and potential updates to x2APIC MSR intercepts. Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly in environments where KVM is used.

Defensive priority

Defenders should prioritize verifying and applying patches for Linux kernel versions affected by this vulnerability, particularly in environments where KVM is used.

Recommended defensive actions

• Verify and apply patches for Linux kernel versions affected by this vulnerability
• Review KVM configurations and ensure AVIC is properly configured
• Monitor system logs for potential DoS attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and associated source item provide details on the vulnerability, including its description, affected versions, and references to patches. However, specific exploitation details or victim information are not provided.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.