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NVD / CVE Program· CNA Linux

CVE-2024-26990: KVM: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.24% (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 2673dfb591a359c75080dd5af3da484b89320d22, cdf811a937471af2d1facdf8ae80e5e68096f1ed, e20bff0f1b2de9cfe303dd35ff46470104a87404; azl3 hyperv-daemons 6.6.22.1-2 on Azure Linux 3.0 6.6.35.1-1; azl3 hyperv-daemons 6.6.35.1-1 on Azure Linux 3.0 6.6.35.1-1.
  • Severity is disputed: the assigning authority (CNA) scores it 8.8, NVD 5.5.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2673dfb591a359c75080dd5af3da484b89320d22, cdf811a937471af2d1facdf8ae80e5e68096f1ed, e20bff0f1b2de9cfe303dd35ff46470104a87404; azl3 hyperv-daemons 6.6.22.1-2 on Azure Linux 3.0 6.6.35.1-1; azl3 hyperv-daemons 6.6.35.1-1 on Azure Linux 3.0 6.6.35.1-1 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: x86/mmu: Write-protect L2 SPTEs in TDP MMU when clearing dirty status Check kvm_mmu_page_ad_need_write_protect() when deciding whether to write-protect or clear D-bits on TDP MMU SPTEs, so that the TDP MMU accounts for any role-specific reasons for disabling D-bit dirty logging. Specifically, TDP MMU SPTEs must be write-protected when the TDP MMU is being used to run an L2 (i.e. L1 has disabled EPT) and PML is enabled. KVM always disables PML when running L2, even when L1 and L2 GPAs are in the some domain, so failing to write-protect TDP MMU SPTEs will cause writes made by L2 to not be reflected in the dirty log. [sean: massage shortlog and changelog, tweak ternary op formatting]

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 1, 2024
Updated
Aug 5, 2026
EPSS
0.2% · 15th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
8.8
3.3 point gap

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

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

Get told when this record changes

  • 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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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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 kernel6.4 and later · before 6.6.29
  • linux linux kernel6.7 and later · before 6.8.8
  • linux linux kernel6.9

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

    • 6.4affected
    • 5982a5392663b30f57ee90b0372c19a7e9cb655a and later · before cdf811a937471af2d1facdf8ae80e5e68096f1edaffected · git
    • 5982a5392663b30f57ee90b0372c19a7e9cb655a and later · before e20bff0f1b2de9cfe303dd35ff46470104a87404affected · git
    • 5982a5392663b30f57ee90b0372c19a7e9cb655a and later · before 2673dfb591a359c75080dd5af3da484b89320d22affected · git
    • before 6.4not affected · semver
    • 6.6.29 and later · up to and including 6.6.*not affected · semver
    • 6.8.8 and later · up to and including 6.8.*not affected · semver
    • 6.9 and laternot affected · original_commit_for_fix

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:13linuxbefore 6.8.9-16.8.9-1

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-2024-26987May 1, 2024 · mm/memory-failure: fix deadlock when hugetlb_optimize_vmemmap is enabled
    22Monitor
  • ← EarlierCVE-2024-26989May 1, 2024 · arm64: hibernate: Fix level3 translation fault in swsusp_save()
    31Monitor
  • Later →CVE-2024-26991May 1, 2024 · KVM: x86/mmu: x86: Don't overflow lpage_info when checking attributes
    22Monitor

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 Linux2673dfb591a359c75080dd5af3da484b89320d22Vendor (CNA)
Linux Linuxcdf811a937471af2d1facdf8ae80e5e68096f1edVendor (CNA)
Linux Linuxe20bff0f1b2de9cfe303dd35ff46470104a87404Vendor (CNA)
azl3 hyperv-daemons 6.6.22.1-2 on Azure Linux 3.06.6.35.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 hyperv-daemons 6.6.35.1-1 on Azure Linux 3.06.6.35.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.8.9-1 · Debian:13Package registry (OSV)

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.

No nightly-computed relations.

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
none
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
High
Availability impact
None

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

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. Fix✗ → ✓

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

References

Show all references (5 more)

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

All records