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NVD / CVE Program· CNA Linux

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

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.13% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 0004ecb798b30e90d7ebfe74efae2d9423315a64, 10063e1251c1485034a018236080792ad083dcc5, 127ccae2c185f62e6ecb4bf24f9cb307e9b9c619.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0004ecb798b30e90d7ebfe74efae2d9423315a64, 10063e1251c1485034a018236080792ad083dcc5, 127ccae2c185f62e6ecb4bf24f9cb307e9b9c619 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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 7.9 · v3.1—No exploit Fix available
Published
May 6, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.9 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.9
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.13 and later · before 5.15.202
  • linux linux kernel5.16 and later · before 6.1.165
  • linux linux kernel6.2 and later · before 6.6.128
  • linux linux kernel6.7 and later · before 6.12.75
  • linux linux kernel6.13 and later · before 6.18.16
  • linux linux kernel6.19 and later · before 6.19.6

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.13affected
    • cc3ed80ae69f454c3d904af9f65394a540099723 and later · before 10063e1251c1485034a018236080792ad083dcc5affected · git
    • cc3ed80ae69f454c3d904af9f65394a540099723 and later · before c3b7015000988ba35ecd5648f4b2283960f00543affected · git
    • cc3ed80ae69f454c3d904af9f65394a540099723 and later · before 3880e331b0b31d0d5d3702b124f6c93539cd478aaffected · git
    • cc3ed80ae69f454c3d904af9f65394a540099723 and later · before fce2fd4a2ca05670a91015aacccf96a1c26268fdaffected · git
    • cc3ed80ae69f454c3d904af9f65394a540099723 and later · before d464cf1ed900d47c85393d40b00017b6adfc2e6caffected · git
    • cc3ed80ae69f454c3d904af9f65394a540099723 and later · before 0004ecb798b30e90d7ebfe74efae2d9423315a64affected · git
    • cc3ed80ae69f454c3d904af9f65394a540099723 and later · before 127ccae2c185f62e6ecb4bf24f9cb307e9b9c619affected · git
    • before 5.13not affected · semver
    • 5.15.202 and later · up to and including 5.15.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.53.1.el10_26.12.0-211.53.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-43131May 6, 2026 · drm/amd/pm: Fix null pointer dereference issue
    22Monitor
  • ← EarlierCVE-2026-43132May 6, 2026 · dm-verity: correctly handle dm_bufio_client_create() failure
    22Monitor
  • Later →CVE-2026-43134May 6, 2026 · Bluetooth: L2CAP: Fix missing key size check for L2CAP_LE_CONN_REQ
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0004ecb798b30e90d7ebfe74efae2d9423315a64Vendor (CNA)
Linux Linux10063e1251c1485034a018236080792ad083dcc5Vendor (CNA)
Linux Linux127ccae2c185f62e6ecb4bf24f9cb307e9b9c619Vendor (CNA)
Linux Linux3880e331b0b31d0d5d3702b124f6c93539cd478aVendor (CNA)
Linux Linuxc3b7015000988ba35ecd5648f4b2283960f00543Vendor (CNA)
Linux Linuxd464cf1ed900d47c85393d40b00017b6adfc2e6cVendor (CNA)
Linux Linuxfce2fd4a2ca05670a91015aacccf96a1c26268fdVendor (CNA)
almalinux:kernel6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.53.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.1.170-1 · Debian:12Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel-matched0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo0:6.12.0-211.53.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

+4

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-39682243 days aparttls: fix handling of zero-length records on the rx_listKEV
    70This week
  • CVE-2026-3163712 days apartrxrpc: reject undecryptable rxkad response tickets
    39Monitor
  • CVE-2026-3166612 days apartbtrfs: fix incorrect return value after changing leaf in lookup_extent_data_ref()
    31Monitor
  • CVE-2026-6384174 days apartdrm/amdgpu/jpeg: set no_user_fence for JPEG v5.0.1 ring
    31Monitor
  • CVE-2026-6384374 days apartdrm/amdgpu/jpeg: set no_user_fence for JPEG v4.0.5 ring
    31Monitor
  • CVE-2026-6384774 days apartdrm/amdgpu/jpeg: set no_user_fence for JPEG v2.5 ring
    31Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
high · the service can be disrupted

Impact can extend beyond the vulnerable component (scope changes).

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality impact
Low
Integrity impact
Low
Availability impact
High

Weakness class (CWE)

CWE-754 · Improper Check for Unusual or Exceptional Conditions

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (14 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records