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

> A privileged guest user can bypass SMRAM protection to inject code into System Management Mode via a QEMU VAPIC validation flaw.

- **Severity:** High 8.2 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Sep 2026
- **Updated:** 21 Sep 2026
- **Also known as:** AZL-105275, DEBIAN-CVE-2026-81627, ECHO-9519-9251-f2aa, GHSA-x7v7-qcr5-q66r, UBUNTU-CVE-2026-81627

## What is CVE-2026-81627?

CVE-2026-81627 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 18 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### 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.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-81627?


## How do I fix CVE-2026-81627?

Apply the vendor's patch.

## Is CVE-2026-81627 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81627 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-81627 and fix it if it is affected.

What it is: CVE-2026-81627 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 18 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-81627 exists.

Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-81627/ (Markdown: https://insights.sbomify.com/CVE-2026-81627/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-81627
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-81627
- OSV: https://osv.dev/vulnerability/CVE-2026-81627

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-81627/
Summaries are generated and may contain mistakes; the official description above is the record.