KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation
Priority LOW 33CWE-754Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · High
- Fix status
- Partial Red Hat: 15 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00133 2nd percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.15.202, 6.1.165, 6.6.128 +4Red Hat: 5 advisoriesRed Hat: 15 fixed, 2 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.13 and later | 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16, 6.19.6, 7.0 | Patch available | CNA |
- Linux VendorLinux Affected 5.13 and later Fixed in 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16, 6.19.6, 7.0 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.13 to before 5.15.202; 5.16 to before 6.1.165; 6.2 to before 6.6.128; 6.7 to before 6.12.75; 6.13 to before 6.18.16; 6.19 to before 6.19.6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.13 to before 5.15.202; 5.16 to before 6.1.165; 6.2 to before 6.6.128; 6.7 to before 6.12.75; 6.13 to before 6.18.16; 6.19 to before 6.19.6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16, 6.19.6, 7.0
Red Hat 5 advisories
- RHSA-2026:66357 Released 2026-09-15 · Red Hat rating ImportantOpenShift Container Platform 4.22.14 bug fix and security update
- Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202609081748-0, rhcos-ppc64le-4.22.9.8.202609081748-0, rhcos-s390x-4.22.9.8.202609081748-0 +1
- RHSA-2026:67468 Released 2026-09-15 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.163.1.el8_10, kernel-4.18.0-553.163.1.el8_10, kernel-abi-stablelists-4.18.0-553.163.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.163.1.el8_10
- RHSA-2026:67469 Released 2026-09-15 · Red Hat rating Importantkernel-rt security update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-core-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-4.18.0-553.163.1.rt7.504.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-core-4.18.0-553.163.1.rt7.504.el8_10, kernel-rt-debug-4.18.0-553.163.1.rt7.504.el8_10 +7
Show 2 more Red Hat advisories
- RHSA-2026:66180 Released 2026-09-10 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.46.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.46.1.el9_8, kernel-64k-devel-5.14.0-687.46.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.46.1.el9_8, kernel-64k-5.14.0-687.46.1.el9_8, kernel-64k-core-5.14.0-687.46.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.46.1.el9_8, libperf-5.14.0-687.46.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-64k-5.14.0-687.46.1.el9_8, kernel-rt-64k-core-5.14.0-687.46.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-core-5.14.0-687.46.1.el9_8, kernel-rt-debug-5.14.0-687.46.1.el9_8 +9
- RHSA-2026:65334 Released 2026-09-08 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.53.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.53.1.el10_2, kernel-64k-devel-6.12.0-211.53.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.53.1.el10_2, kernel-64k-6.12.0-211.53.1.el10_2, kernel-64k-core-6.12.0-211.53.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.53.1.el10_2, libperf-6.12.0-211.53.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.53.1.el10_2, kernel-rt-64k-6.12.0-211.53.1.el10_2, kernel-rt-64k-core-6.12.0-211.53.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.53.1.el10_2, kernel-rt-core-6.12.0-211.53.1.el10_2, kernel-rt-debug-6.12.0-211.53.1.el10_2 +9
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:67468 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:67468 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:67469 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:67469 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:65334 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat OpenShift Container Platform 4.22 | Fixed | RHSA-2026:66357 |
Not affected: 3 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-43133
- 2026-10-03 Alias added: GHSA-g9j5-v9rr-m845
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-19 Weakness changed · CISA ADP
References
Patch 7
- https://git.kernel.org/stable/c/10063e1251c1485034a018236080792ad083dcc5
- https://git.kernel.org/stable/c/c3b7015000988ba35ecd5648f4b2283960f00543
- https://git.kernel.org/stable/c/3880e331b0b31d0d5d3702b124f6c93539cd478a
- https://git.kernel.org/stable/c/fce2fd4a2ca05670a91015aacccf96a1c26268fd
- https://git.kernel.org/stable/c/d464cf1ed900d47c85393d40b00017b6adfc2e6c
- https://git.kernel.org/stable/c/0004ecb798b30e90d7ebfe74efae2d9423315a64
- https://git.kernel.org/stable/c/127ccae2c185f62e6ecb4bf24f9cb307e9b9c619
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Sources
- CVE-2026-43133 · CVE Program
- CVE-2026-43133 · NVD
- FIRST EPSS
- GHSA-g9j5-v9rr-m845 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-43133 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences