CVE-2026-89932 Linux CVE debrief

Who should care

Defenders responsible for Linux environments that utilize KVM and nVMX should assess exposure and prioritize patching or mitigation. This includes administrators of virtualized infrastructure and Linux system maintainers.

Why it matters

Defenders should prioritize patching or mitigating this vulnerability in Linux environments that utilize KVM and nVMX due to potential security issues and unexpected behavior from stale TLB entries.

• Potential use of stale TLB entries in virtualized environments
• Unexpected behavior or security issues in KVM and nVMX implementations
• Need for patching or mitigation in Linux environments
• Verification of system exposure and version checks

Technical summary

The Linux kernel's KVM subsystem has a vulnerability in the nVMX implementation related to the handling of vpid02. When a VPID is reused, associated TLB entries might not be properly flushed, potentially leading to the use of stale TLB entries. This issue has been addressed through patches provided by the Linux kernel maintainers. The vulnerability affects Linux environments utilizing KVM and nVMX, and defenders should prioritize patching or mitigating this vulnerability, especially in virtualized infrastructure. The issue involves the potential use of stale TLB entries in virtualized environments, leading to unexpected behavior or security issues.

Defensive priority

Defenders should prioritize patching or mitigating this vulnerability in Linux environments that utilize KVM and nVMX, especially in virtualized infrastructure.

Recommended defensive actions

• Assess exposure in Linux environments utilizing KVM and nVMX
• Verify if the system is using affected versions of the Linux kernel
• Apply patches or updates provided by the Linux kernel maintainers
• Monitor virtualized environments for unexpected behavior
• 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 and affected versions. However, specific information on exploitation or impact is limited. Defenders should verify system exposure, review vendor guidance, and assess potential security issues from stale TLB entries in virtualized environments. The vulnerability affects Linux environments utilizing KVM and nVMX, and patching or mitigation is recommended. Evidence from the CVE Program and NVD detail pages supports this assessment,

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.