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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.9 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-628
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0004ecb798b30e90d7ebfe74efae2d9423315a64Patch
- https://git.kernel.org/stable/c/10063e1251c1485034a018236080792ad083dcc5Patch
- https://git.kernel.org/stable/c/127ccae2c185f62e6ecb4bf24f9cb307e9b9c619Patch
- https://git.kernel.org/stable/c/3880e331b0b31d0d5d3702b124f6c93539cd478aPatch
- https://git.kernel.org/stable/c/c3b7015000988ba35ecd5648f4b2283960f00543Patch
- https://git.kernel.org/stable/c/d464cf1ed900d47c85393d40b00017b6adfc2e6cPatch
- https://git.kernel.org/stable/c/fce2fd4a2ca05670a91015aacccf96a1c26268fdPatch
- https://access.redhat.com/errata/RHSA-2026:65334
- https://access.redhat.com/errata/RHSA-2026:66180
- https://access.redhat.com/security/cve/CVE-2026-43133
- https://bugzilla.redhat.com/show_bug.cgi?id=2467065
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-43133.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.