How severe is CVE-2026-43133?

CVE-2026-43133 has a CVSS 3.x base score of 7.9, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability high.

Is CVE-2026-43133 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-43133?

CVE-2026-43133 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-43133?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-43133 have an EU (EUVD) identifier?

Yes. CVE-2026-43133 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27695.

When was CVE-2026-43133 published?

CVE-2026-43133 was published on 2026-05-06 and last updated on 2026-06-30.

CVE-2026-43133

CVE-2026-43133 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-628.

Key facts

Severity: High (CVSS 3.x base score 7.9)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-27695
Weakness: CWE-628
Affected product: Linux Linux Kernel
Published: 2026-05-06
Last modified: 2026-06-30

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.

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 3.x base score of 7.9, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability high.
Is CVE-2026-43133 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-43133?: CVE-2026-43133 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-43133?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-43133 have an EU (EUVD) identifier?: Yes. CVE-2026-43133 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-27695.
When was CVE-2026-43133 published?: CVE-2026-43133 was published on 2026-05-06 and last updated on 2026-06-30.

References

Affected products (1)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

More vulnerabilities in Linux Linux Kernel

CVE-2023-2163 — Critical (CVSS 10.0): Incorrect verifier pruning in BPF in Linux Kernel >=5.4 leads to unsafe code paths being incorrectly marked as safe,…
CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
CVE-2015-1421 — Critical (CVSS 10.0): Use-after-free vulnerability in the sctp_assoc_update function in net/sctp/associola.c in the Linux kernel before…
CVE-2014-2523 — Critical (CVSS 10.0): net/netfilter/nf_conntrack_proto_dccp.c in the Linux kernel through 3.13.6 uses a DCCP header pointer incorrectly,…
CVE-2010-2495 — Critical (CVSS 10.0): The pppol2tp_xmit function in drivers/net/pppol2tp.c in the L2TP implementation in the Linux kernel before 2.6.34 does…
CVE-2010-2521 — Critical (CVSS 10.0): Multiple buffer overflows in fs/nfsd/nfs4xdr.c in the XDR implementation in the NFS server in the Linux kernel before…

All CVEs affecting Linux Linux Kernel →

Other CWE-628 vulnerabilities

CVE-2019-14844 — High (CVSS 7.5): A flaw was found in, Fedora versions of krb5 from 1.16.1 to, including 1.17.x, in the way a Kerberos client could crash…
CVE-2019-7303 — High (CVSS 7.5): A vulnerability in the seccomp filters of Canonical snapd before version 2.37.4 allows a strict mode snap to insert…
CVE-2025-0325 — Medium (CVSS 4.3): A Guard Tour VAPIX API parameter allowed the use of arbitrary values and can be incorrectly called, allowing an…

Browse all CWE-628 vulnerabilities →