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CVE Record

CVE-2026-43133: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation

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.

HighCVSS 7.9Not KEV-listedUpdated
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Potential ATT&CK relevance

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cwe · low confidence lookup

CWE-628: Exact CWE lookup

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CVE-2026-43133 mapping review

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Vulnerability profileCVE Program record
Severity
High
CVSS
7.9 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

2CVSS vectors
5Timeline events
2ADP providers
16Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

2 official scores

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
7.9CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H25.3Linux
7.9CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H25.3redhat-SADP

Vulnerability scoring details

Base CVSS 3.1 score

7.9High
CVSS 3.1 vector shape for CVE-2026-43133Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. ADP timelineredhat-SADP

    Reported to Red Hat.

  3. ADP timelineredhat-SADP

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

redhat-SADPkernel: KVM: nSVM: Always use vmcb01 in VMLOAD/VMSAVE emulation
other:Red Hat severity ratingcvssV3_1
  • 2026-05-06T00:00:00.000Z: Reported to Red Hat.
  • 2026-05-06T00:00:00.000Z: Made public.
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxcc3ed80ae69f454c3d904af9f65394a540099723, cc3ed80ae69f454c3d904af9f65394a540099723, cc3ed80ae69f454c3d904af9f65394a540099723, cc3ed80ae69f454c3d904af9f65394a540099723, cc3ed80ae69f454c3d904af9f65394a540099723, cc3ed80ae69f454c3d904af9f65394a540099723, cc3ed80ae69f454c3d904af9f65394a540099723unaffected
LinuxLinux5.13, 0, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.16, 6.19.6, 7.0affected
Weakness

CWE details

CWE-628

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.