CVE-2026-43133
KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation
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.
INFO
Published Date :
May 6, 2026, 12:16 p.m.
Last Modified :
May 8, 2026, 5:25 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Apply the KVM patch for nSVM.
- Ensure VMLOAD/VMSAVE emulation uses vmcb01.
- Update the Linux kernel to the latest version.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-43133.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-43133 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-43133
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-43133 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-43133 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
May. 08, 2026
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.128 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.75 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.16 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.6 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.165 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.13 up to (excluding) 5.15.202 Added Reference Type kernel.org: https://git.kernel.org/stable/c/0004ecb798b30e90d7ebfe74efae2d9423315a64 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/10063e1251c1485034a018236080792ad083dcc5 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/127ccae2c185f62e6ecb4bf24f9cb307e9b9c619 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/3880e331b0b31d0d5d3702b124f6c93539cd478a Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/c3b7015000988ba35ecd5648f4b2283960f00543 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d464cf1ed900d47c85393d40b00017b6adfc2e6c Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/fce2fd4a2ca05670a91015aacccf96a1c26268fd Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 08, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 06, 2026
Action Type Old Value New Value Added 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. Added Reference https://git.kernel.org/stable/c/0004ecb798b30e90d7ebfe74efae2d9423315a64 Added Reference https://git.kernel.org/stable/c/10063e1251c1485034a018236080792ad083dcc5 Added Reference https://git.kernel.org/stable/c/127ccae2c185f62e6ecb4bf24f9cb307e9b9c619 Added Reference https://git.kernel.org/stable/c/3880e331b0b31d0d5d3702b124f6c93539cd478a Added Reference https://git.kernel.org/stable/c/c3b7015000988ba35ecd5648f4b2283960f00543 Added Reference https://git.kernel.org/stable/c/d464cf1ed900d47c85393d40b00017b6adfc2e6c Added Reference https://git.kernel.org/stable/c/fce2fd4a2ca05670a91015aacccf96a1c26268fd