---
id: CVE-2026-98720
title: 'KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified'
summary: |-
  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 control…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e <
    2db11598b59f16ddb6420693f9a4ac4efc3d4789
  - >-
    Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e <
    f6189e26d0237e47e2f04f9cb1e43fd19a9b2f3a
  - >-
    Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e <
    1e497e3bdab6983deb68a1d26b488027deb4527f
  - >-
    Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e <
    2abb25273c82061dd4670690c81c319c03740bf6
  - Linux 5.17
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:46:55.863Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98720'
references:
  - url: 'https://git.kernel.org/stable/c/2db11598b59f16ddb6420693f9a4ac4efc3d4789'
  - url: 'https://git.kernel.org/stable/c/f6189e26d0237e47e2f04f9cb1e43fd19a9b2f3a'
  - url: 'https://git.kernel.org/stable/c/1e497e3bdab6983deb68a1d26b488027deb4527f'
  - url: 'https://git.kernel.org/stable/c/2abb25273c82061dd4670690c81c319c03740bf6'
tags:
  - cve.org
ingestedAt: '2026-10-18T16:47:32.510Z'
---

## Overview

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.

## Affected

- `Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e < 2db11598b59f16ddb6420693f9a4ac4efc3d4789`
- `Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e < f6189e26d0237e47e2f04f9cb1e43fd19a9b2f3a`
- `Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e < 1e497e3bdab6983deb68a1d26b488027deb4527f`
- `Linux >= 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e < 2abb25273c82061dd4670690c81c319c03740bf6`
- `Linux 5.17`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.