What is CVE-2026-81627?

CVE-2026-81627 is a high-severity vulnerability in Red Hat Enterprise Linux 10, classified under Out-of-bounds Write. CVSS score: 8.2/10. Published 2026-09-18.

How severe is CVE-2026-81627?

High severity. CVSS v3 base score is 8.2 out of 10.

Buffer overflow in Red Hat Enterprise Linux 10

CVE-2026-81627

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.

Vulnerability class: Buffer Overflow

Published 2026-09-18 · last modified 2026-10-30.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (8.9th percentile), scored 2026-11-02.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

access.redhat.com/security/cve/CVE-2026-81627 (vdb-entry)
bugzilla.redhat.com/show_bug.cgi (issue-tracking)
gitlab.com/qemu-project/qemu/-/work_items/4206

Frequently asked questions

What is CVE-2026-81627?: CVE-2026-81627 is a high-severity vulnerability in Red Hat Enterprise Linux 10, classified under Out-of-bounds Write. CVSS score: 8.2/10. Published 2026-09-18.
How severe is CVE-2026-81627?: High severity. CVSS v3 base score is 8.2 out of 10.