---
id: CVE-2026-81627
title: A flaw was found in QEMU
summary: >-
  A flaw was found in QEMU. The VAPIC setup hypercall in hw/i386/vapic.c does
  not validate that the writable RAM alias remains within the option ROM window.
  A privileged guest user on a Q35/KVM machine can position this alias over
  locked S…
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-787
vendor: Red Hat
product: qemu-kvm
affected:
  - qemu-kvm (all versions)
  - qemu-kvm
  - qemu-kvm (all versions)
  - qemu-kvm-ma (all versions)
  - 'virt-devel:rhel/qemu-kvm (all versions)'
  - 'virt:rhel/qemu-kvm (all versions)'
  - qemu-kvm (all versions)
  - qemu-kvm
  - openshift/ose-rhel-coreos-8 (all versions)
  - openshift/ose-rhel-coreos-9 (all versions)
  - qemu-kvm-rhev (all versions)
published: '2026-09-18'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T12:17:20.197'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81627'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-81627'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2536950'
    label: secalert@redhat.com
  - url: 'https://gitlab.com/qemu-project/qemu/-/work_items/4206'
    label: secalert@redhat.com
  - url: 'https://gitlab.com/qemu-project/qemu/-/work_items/4206'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-81627.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-81627'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-81627'
tags:
  - nvd
  - cve.org
  - exploit-available
  - csaf
  - vex
  - red-hat
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T15:07:17.054544Z'
epss: 0.00192
epssPercentile: 0.07847
ingestedAt: '2026-09-18T11:40:03.680Z'
---

## Overview

A flaw was found in QEMU. The VAPIC setup hypercall in hw/i386/vapic.c does not validate that the writable RAM alias remains within the option ROM window. A privileged guest user on a Q35/KVM machine can position this alias over locked SMRAM, bypassing chipset D_LCK protection and injecting code into System Management Mode memory.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat Enterprise Linux for NVIDIA 26, Red Hat OpenShift Container Platform 4, … · no fix planned: Red Hat Enterprise Linux for NVIDIA 26, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-81627.json)