CVE-2026-45944: iommu/vt-d: Clear Present bit before tearing down context entry

mediumCVSS 5.5CVE-2026-45944

CSIRTS triage

vendor: Linux product: Linux Kernel Memory corruption

What: The iommu/vt-d driver fails to clear the Present bit before tearing down a context entry, potentially causing memory corruption.
Who is affected: Systems running affected Linux kernel versions with Intel VT-d IOMMU enabled.
Urgency: Medium severity (CVSS 5.5) and not currently exploited; standard patching schedule applies.
Action: Apply kernel patch or update to a kernel version containing the fix for CVE-2026-45944.

AI-assisted analysis generated from the source advisory — verify against the original.

⚡ Watch Linux Kernel

Get an email when a new Linux Kernel advisory drops — max one per day, one-click unsubscribe.

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 5.5
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45944

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-459440.13% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 3% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-45944	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[UPDATE] [high] Linux Kernel: Multiple Vulnerabilitiescert-bund
unknownMultiple vulnerabilities in Debian Linux kernel (August 07, 2026)cert-fr-avis
unknownDSA-6405-1 linux - security updatedebian

Recent advisories for iommu/vt-d

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

unknownCVE-2026-64591: In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Avoid WARNING …nvd · 2026-08-06
highCVE-2026-45894: iommu/vt-d: Clear Present bit before tearing down PASID entrymsrc · 2026-08-06
mediumCVE-2026-43161: iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable modemsrc · 2026-08-06
mediumCVE-2025-21833: iommu/vt-d: Avoid use of NULL after WARN_ON_ONCEmsrc · 2026-08-06
mediumCVE-2024-27079: iommu/vt-d: Fix NULL domain on device releasemsrc · 2026-08-06
unknownCVE-2026-53372: In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Block PASID at…nvd · 2026-07-19