Skip to main content
VulnerabilityPublished Updated

CVE-2026-81627: Red Hat Enterprise Linux 10 · Out-of-bounds Write

Affects Red Hat Enterprise Linux 10Source CVE Database V5

0
Compare

Not known to be exploited · CVSS 8.2 High.

Data as of 2 Nov 2026, 11:12 UTC

CVSS 3.1 base score
8.2High
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (redhat)CVSS 3.18.2
EPSS
0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 18 Sep 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2 Nov 2026.

What to do

Affected software

ProductAffectedFixed in
Red Hat Enterprise Linux 10qemu-kvmAffected–Fixed in–
Red Hat Enterprise Linux 6qemu-kvmAffected–Fixed in–
Red Hat Enterprise Linux 7qemu-kvmAffected–Fixed in–
Red Hat Enterprise Linux 7qemu-kvm-maAffected–Fixed in–
Red Hat Enterprise Linux 8virt-devel:rhel/qemu-kvmAffected–Fixed in–
Red Hat Enterprise Linux 8virt:rhel/qemu-kvmAffected–Fixed in–

AI-suggested

Red Hat advises disabling the VAPIC TPR optimization to mitigate this vulnerability. This can be done by preventing the kvmvapic option ROM from loading. For libvirt-managed guests, add the following to the guest's domain XML: <features> <apic/> <hyperv> <vapic state='off'/> </hyperv></features>. For direct QEMU usage, pass the command line option '-global kvmvapic.rom=off'. This mitigation affects only 32-bit Windows guests using MMIO-based TPR register access and does not impact Linux guests, 64-bit Windows guests, or guests using x2APIC or MSR-based TPR access.

Description

CVE-2026-81627 is a vulnerability in QEMU affecting Red Hat Enterprise Linux 10 where a privileged guest user on a Q35/KVM machine can exploit improper validation in the VAPIC setup hypercall to bypass chipset D_LCK protection and inject code into System Management Mode (SMM) memory. This flaw allows code injection into locked SMRAM by positioning a writable RAM alias outside the option ROM window. Exploitation requires guest root access and KVM acceleration. The vulnerability is rated high severity with a CVSS score of 8.2. Mitigation involves disabling the VAPIC TPR optimization by preventing the kvmvapic option ROM from loading, which affects only 32-bit Windows guests using MMIO-based TPR register access.

References

Community reviews

Loading reviews…