CVE-2026-43133
Published: May 7, 2026Last modified: May 7, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.9 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | CHANGED |
| Confidentiality | LOW |
| Integrity impact | LOW |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.167-r0) |
| 25 LTS | linux-lts | Fixed (6.12.80-r0) | |
| Stream | linux-lts | Fixed (6.12.76-r0) |
References
- https://git.kernel.org/stable/c/0004ecb798b30e90d7ebfe74efae2d9423315a64
- https://git.kernel.org/stable/c/10063e1251c1485034a018236080792ad083dcc5
- https://git.kernel.org/stable/c/127ccae2c185f62e6ecb4bf24f9cb307e9b9c619
- https://git.kernel.org/stable/c/3880e331b0b31d0d5d3702b124f6c93539cd478a
- https://git.kernel.org/stable/c/c3b7015000988ba35ecd5648f4b2283960f00543
- https://git.kernel.org/stable/c/d464cf1ed900d47c85393d40b00017b6adfc2e6c
- https://git.kernel.org/stable/c/fce2fd4a2ca05670a91015aacccf96a1c26268fd