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Vulnerability · Published Sep 18, 2026 · Assigned by redhat

CVE-2026-81627Qemu-kvm: vapic writable rom alias can escape the option-rom window and expose locked smram

High 8.2

In plain English

A high-severity out-of-bounds write in Red Hat Enterprise Linux 10 from Red Hat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High
Exploit odds (30 days)0.2%top 91.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12qemuno fix listedDEBIAN-CVE-2026-81627
Debian:13qemuno fix listedDEBIAN-CVE-2026-81627
Debian:14qemu1:11.1.2+ds-1DEBIAN-CVE-2026-81627
Ubuntu:22.04:LTSqemuno fix listedUBUNTU-CVE-2026-81627
Ubuntu:24.04:LTSqemuno fix listedUBUNTU-CVE-2026-81627
Ubuntu:26.04:LTSqemuno fix listedUBUNTU-CVE-2026-81627
Ubuntu:26.10qemuno fix listedUBUNTU-CVE-2026-81627
Ubuntu:26.04:LTSqemu-hweno fix listedUBUNTU-CVE-2026-81627
Ubuntu:26.10qemu-hweno fix listedUBUNTU-CVE-2026-81627

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 6 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 7 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Enterprise Linux for NVIDIA 26 see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 4 see references
Red Hat Red Hat OpenShift Container Platform 5 see references
Red Hat Red Hat OpenStack Platform 13 (Queens) see references

Weakness: CWE-787 · Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

References