CVE-2026-81627CWE-787

CVE-2026-81627

High · published September 18, 2026

CVSS v3.1
8.2
EPSS
0%
Percentile
8.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.2 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00192 · 8.4th percentile
Weakness
CWE-787 · Out-of-bounds Write
Published
2026-09-18T15:17Z
References (4)
https://gitlab.com/qemu-project/qemu/-/work_items/4206 · [email protected]https://gitlab.com/qemu-project/qemu/-/work_items/4206 · 134c704f-9b21-4f2e-91b3-4a467353bcc0https://access.redhat.com/security/cve/CVE-2026-81627 · [email protected]https://bugzilla.redhat.com/show_bug.cgi?id=2536950 · [email protected]
EPSS history
Timeline
  • 20 SEP 03:24Z
    EPSS moved — → 0%
    epss
  • 18 SEP 10:54Z
    Qemu-kvm: vapic writable rom alias can escape the option-rom window and expose locked smram
    cvelistv5