CVE-2026-43348

VTL0 memory registration failure via oversized folio order

Published May 8, 2026 · Updated May 8, 2026

Availability flaw in Linux Kernel 6.19 through 7.0.1 allows local users to make VTL0 memory registration fail with EINVAL. The mshv_vtl add-memory ioctl derives pgmap->vmemmap_shift from endpoint alignment without clamping it to MAX_FOLIO_ORDER, so memremap_pages rejects a highly aligned range. A local user able to invoke MSHV_ADD_VTL0_MEMORY with such a range can prevent that VTL0 memory range from being registered; no data disclosure or modification is reported.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Availability flaw in Linux Kernel 6.19 through 7.0.1 allows local users to make VTL0 memory registration fail with EINVAL. The mshv_vtl add-memory ioctl derives pgmap->vmemmap_shift from endpoint alignment without clamping it to MAX_FOLIO_ORDER, so memremap_pages rejects a highly aligned range. A local user able to invoke MSHV_ADD_VTL0_MEMORY with such a range can prevent that VTL0 memory range from being registered; no data disclosure or modification is reported.

The record

CVE
CVE-2026-43348
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.19
  2. Affected versionversion=7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f <404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd
  3. Affected versionversion=7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f <a142ca4b6481e71498712800b20e0c0fcf02843b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.19; version=7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f <404cd6bffe17e25e0f94ed2775ffdd6cd10ac3fd; version=7bfe3b8ea6e30437e01fcb8e4f56ef6e4d986d0f <a142ca4b6481e71498712800b20e0c0fcf02843b

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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