CVE-2026-98720

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified

Force a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the

runtime eVMCS controls (pin, primary, secondary, etc.) are being updated.

If L1 isn't intercepting TPR writes, runs L2 with TPR virtualization, and

then runs the same L2 with TPR virtualization disabled, KVM will fail to

refresh msr_bitmap02 and leave TPR in passthrough mode even though TPR

virtualization is disabled. I.e. failure to refresh the bitmap lets L2 (or

L1 by proxy) read and write L0's TPR.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References