CVE-2026-64287 Linux CVE debrief

Who should care

System administrators and security teams responsible for Linux systems using KVM on arm64 architecture should assess their exposure and apply patches or mitigations as necessary. This includes reviewing system configurations, monitoring for suspicious activity, and implementing compensating controls where needed. Additionally, security teams should prioritize patching and mitigation efforts based on the potential impact of the vulnerability on their组织的' 资产

Why it matters

This vulnerability in the Linux kernel's KVM implementation for arm64 architecture could allow attackers with high privileges to potentially execute arbitrary code or cause denial of service. System administrators and security teams should assess their exposure, especially if they use KVM on arm64 systems, and apply patches or mitigations as necessary.

• Potential code execution with high privileges
• Possible denial of service through system crash or instability
• Increased risk of lateral movement or privilege escalation

Technical summary

The Linux kernel's KVM implementation for arm64 architecture has a vulnerability that could allow an attacker with high privileges to execute arbitrary code or cause a denial of service. The issue arises from the improper bounding of the `used_lrs` variable when flushing the pKVM hyp vCPU. This vulnerability can be addressed by applying patches provided by Linux kernel maintainers, which clamp used_lrs to the number of implemented list registers after copying the host vGIC state into the hyp's private vCPU. Technical details involve the handling of vgic_v3 and the need to enforce bounds checking to prevent out-of-bounds access.

Defensive priority

High

Recommended defensive actions

• Review and apply patches from Linux kernel maintainers
• Restrict access to KVM on arm64 systems to trusted users
• Monitor system logs for suspicious activity
• Consider implementing compensating controls such as additional authentication or access controls
• Perform vulnerability assessments to identify exposed systems
• Implement asset inventory management to track affected systems
• Establish a change management process for remediation

Evidence notes

The vulnerability is described in the CVE record and source item. Linux kernel developers have addressed the issue through commits 2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8, 9fa301d8298778dd799fa4dcf7a7f440715d146e, c646431865f4b1a5b14067233fa27b11e05e0d46, 7fca3fcef81c713bc82a37bf741e0f28e6d04a6f, and 8cc8bbbfab14c22c5551d0dd19b208a44b141c76.

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.