CVE-2026-46317 Linux CVE debrief

Who should care

Defenders managing Linux KVM environments on arm64 architectures should assess exposure and apply patches. This includes administrators of virtualized environments, cloud infrastructure providers, and Linux system administrators.

Why it matters

This vulnerability in Linux KVM for arm64 could allow local attackers to escalate privileges or cause denial of service within virtual machine environments, impacting confidentiality, integrity, and availability.

• Privilege escalation within virtual machines
• Denial of service in shared virtual machine environments
• Potential for unauthorized access to sensitive data

Technical summary

The Linux kernel's KVM for arm64 did not properly synchronize access to the nested_mmus array, allowing for potential use-after-free vulnerabilities. An attacker with local access and limited privileges could potentially exploit this to escalate privileges or cause a denial of service. This issue has been addressed by reassigning the nested_mmus array behind the mmu_lock, ensuring that the array is not accessed after it has been freed. Defenders managing Linux KVM environments on arm64 architectures should assess exposure and apply patches. This includes administrators of virtualized environments, cloud infrastructure providers, and Linux system administrators.

Defensive priority

Defenders should prioritize assessing exposure and applying patches for Linux KVM on arm64 architectures, particularly in environments where untrusted users have access to virtual machines.

Recommended defensive actions

• Assess exposure of Linux KVM on arm64 architectures in your environment.
• Verify if your Linux distributions or custom kernels are affected by checking version numbers.
• Apply patches or updates provided by Linux distributions or vendors.
• Monitor virtual machine environments for unusual activity or privilege escalation 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.

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 details about exploitation or impact are limited.

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.