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CVE-2026-43133

HIGHCVSS 7.9/10EPSS 0.12%

Last modified

CVE-2026-43133 is a high-severity vulnerability rated 7.9/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation Commit cc3ed80ae69f ("KVM: nSVM: always use vmcb01 to for vmsave/vmload of guest state") made KVM always use vmcb01 for the fields controlled by VMSAVE/VMLOAD, but it missed updating the VMLOAD/VMSAVE emulation code to always use vmcb01. As a result, if VMSAVE/VMLOAD is executed by an L2 guest and is not intercepted by L1, KVM will mistakenly use vmcb02. Always use vmcb01 instead of the current VMCB.. EPSS estimates a 0.12% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation Commit cc3ed80ae69f ("KVM: nSVM: always use vmcb01 to for vmsave/vmload of guest state") made KVM always use vmcb01 for the fields controlled by VMSAVE/VMLOAD, but it missed updating the VMLOAD/VMSAVE emulation code to always use vmcb01. As a result, if VMSAVE/VMLOAD is executed by an L2 guest and is not intercepted by L1, KVM will mistakenly use vmcb02. Always use vmcb01 instead of the current VMCB.

Metrics

CVSS 3.1
7.9/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H

EPSS Probability
0.12%

2.3th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 5.13, < 5.15.202
LinuxLinux Kernel>= 5.16, < 6.1.165
LinuxLinux Kernel>= 6.2, < 6.6.128
LinuxLinux Kernel>= 6.7, < 6.12.75
LinuxLinux Kernel>= 6.13, < 6.18.16
LinuxLinux Kernel>= 6.19, < 6.19.6

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-43133?
In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation Commit cc3ed80ae69f ("KVM: nSVM: always use vmcb01 to for vmsave/vmload of guest state") made KVM always use vmcb01 for the fields controlled by VMSAVE/VMLOAD, but it missed updating the VMLOAD/VMSAVE emulation code to always use vmcb01. As a result, if VMSAVE/VMLOAD is executed by an L2 guest and is not intercepted by L1, KVM will mistakenly use vmcb02. Always use vmcb01 instead of the current VMCB.
How severe is CVE-2026-43133?
CVE-2026-43133 has a CVSS score of 7.9/10 (HIGH severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.
How do I fix CVE-2026-43133?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-43133?

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Source: NVD / NIST