CVE-2026-90243

High

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present bit before tearing down copied context entry copied_context_tear_down() zeroes the 128-bit context entry with context_clear_entry() while the Present bit is still set, and only then issues the context-cache and IOTLB invalidations. This leaves a window in which hardware can fetch a torn entry, with some fields already zeroed while Present is still set, leading to unpredictable behaviour or spurious faults. While x86 provides strong write ordering, the compiler may reorder the writes to the two 64-bit halves of the entry, and the hardware fetch is not guaranteed to be atomic with respect to multiple CPU writes. There is no cacheline flush before the invalidation either, so on an IOMMU without coherent access to the context table the zeroed entry may not be visible to hardware at the point the invalidation is submitted. Apply the same ownership handshake described in the VT-d spec, Section 6.5.3.3 ("Guidance to Software for Invalidations"): clear only the Present bit, flush it out to the IOMMU, perform the invalidations, and only then zero the remainder of the entry.

Package Linux Kernel
Published 2026-09-17
Last modified 2026-09-18
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

8.1

out of 10
High
Attack Vector
Local
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Affected versions

Linux kernel versions 6.12 and later are affected. Fixed in 6.12.110, 6.18.52, 7.2.6, 7.3-rc1 and their respective stable series.

Affected from
≥ 6.12
Fixed in
✓ 6.12.110 6.12.x ✓ 6.18.52 6.18.x ✓ 7.2.6 7.2.x ✓ 7.3-rc1

References

4 total

Frequently asked questions

  • What is CVE-2026-90243?

    CVE-2026-90243 is a High severity Linux kernel vulnerability with a CVSS score of 8.1 out of 10 . It affects Linux kernel versions from 6.12 onward and has been patched in 6.12.110, 6.18.52, 7.2.6 and others. CVE-2026-90243 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-90243?

    CVE-2026-90243 has a CVSS score of 8.1 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H .

  • Is there a patch available for CVE-2026-90243?

    Yes. CVE-2026-90243 has been patched. Fixed versions include 6.12.110, 6.18.52, 7.2.6 and others. If you are running Linux kernel 6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-90243 actively exploited?

    No. CVE-2026-90243 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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