CVE-2026-46071
kernel: KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12
Severity
LowRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 27, 2026
Updated · June 28, 2026
Description
A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) subsystem, specifically affecting its nested virtualization (nSVM) capabilities. The issue arises from incorrect handling of Virtual Machine Control Block Last Branch Record (VMCB_LBR) data when copied to vmcb12, an operation that is not architecturally defined. This can lead to unexpected behavior or instability within nested virtualized environments, potentially impacting the reliability of guest virtual machines.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-440 · Expected Behavior Violation