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.
Published: 2026-10-18
Score: 5.3 Medium
EPSS: < 1% Very Low
KEV: No
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Remediation

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4850-1 linux-6.12 security update
History

Fri, 23 Oct 2026 00:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-270
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H'}

threat_severity

Moderate


Sun, 18 Oct 2026 19:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-665

Sun, 18 Oct 2026 16:00:00 +0000

Type Values Removed Values Added
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.
Title KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-19T09:24:31.090Z

Reserved: 2026-09-25T10:25:14.366Z

Link: CVE-2026-98720

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:25.583

Modified: 2026-10-19T10:19:36.230

Link: CVE-2026-98720

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-18T00:00:00Z

Links: CVE-2026-98720 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-19T11:15:06Z

Weaknesses