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Findings

CVE-2026-43348

In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER When registering VTL0 memory via MSHV_ADD_VTL…

Published May 8, 2026 · corrected/updated Jun 17, 2026 · linux linux kernel · evidence confidence medium

In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and last_pfn, intending to use the largest compound page order both endpoints are aligned to. However, this value is not clamped to MAX_FOLIO_ORDER, so a sufficiently aligned range (e.g. physical range [0x800000000000, 0x800080000000), corresponding to start_pfn=0x800000000 with 35 trailing zeros) can produce a shift larger than what memremap_pages() accepts, triggering a WARN and returning -EINVAL: WARNING: ... memremap_pages+0x512/0x650 requested folio size unsupported The MAX_FOLIO_ORDER check was added by commit 646b67d57589 ("mm/memremap: reject unreasonable folio/compound page sizes in memremap_pages()"). Fix this by clamping vmemmap_shift to MAX_FOLIO_ORDER so we always request the largest order the kernel supports, in those cases, rather than an out-of-range value. Also fix the error path to propagate the actual error code from devm_memremap_pages() instead of hard-coding -EFAULT, which was masking the real -EINVAL return.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-43348 is a medium public vulnerability record for linux linux kernel. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether linux linux kernel is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: linux/linux kernel. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 5.5. It is not currently listed in the CISA Known Exploited catalog. Sources contributing to this record: cve_org, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 8, 2026 · NIST NVD

    Detected

    In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and last_pfn, intending to use the largest compound page order both endpoints are aligned to. However, this value is not clampe

  2. Jun 17, 2026 · NIST NVD

    Updated

    In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and last_pfn, intending to use the largest compound page order both endpoints are aligned to. However, this value is not clampe

Affected

  • cpe linux/linux kernelversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2026-43348

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-43348

    In the Linux kernel, the following vulnerability has been resolved: mshv_vtl: Fix vmemmap_shift exceeding MAX_FOLIO_ORDER When registering VTL0 memory via MSHV_ADD_VTL0_MEMORY, the kernel computes pgmap->vmemmap_shift as the number of trailing zeros in the OR of start_pfn and l

    nvd.nist.gov

References