---
id: CVE-2026-80975
title: >-
  kernel: mfd: qnap-mcu: keep the reply buffer alive past a command timeout
  (CVE-2026-80975)
summary: >-
  A flaw was found in the Linux kernel's `qnap-mcu` driver. This vulnerability
  occurs when the driver processes commands and a reply from the Microcontroller
  Unit (MCU) arrives after a command has timed out or failed. The driver may
  write th…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe: CWE-562
vendor: Red Hat
product: Red Hat OpenShift Container Platform 4
affected:
  - openshift_container_platform 4
published: '2026-09-11'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T18:37:43+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80975.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80975.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-80975'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532227'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-80975'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80975'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80975.mbox
  - url: 'https://git.kernel.org/stable/c/0b6680e306397097a97767447368221fac753809'
  - url: 'https://git.kernel.org/stable/c/47504742cea7878ebd1bf1491bbed923df6b90b1'
  - url: 'https://git.kernel.org/stable/c/8391ee06d08845a0a165b5fe679ba326915166b2'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00161
epssPercentile: 0.05758
scores:
  vendor: 5.7
  cna: 7.8
ingestedAt: '2026-09-14T15:23:07.476Z'
---

## Overview

A flaw was found in the Linux kernel's `qnap-mcu` driver. This vulnerability occurs when the driver processes commands and a reply from the Microcontroller Unit (MCU) arrives after a command has timed out or failed. The driver may write this late or unsolicited message into a memory area that is no longer in use, leading to memory corruption. This can result in system instability or a denial of service.

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-14 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80975.json)

**kernel: mfd: qnap-mcu: keep the reply buffer alive past a command timeout** — rated Moderate by Red Hat. Released 2026-09-11, updated 2026-09-14.

Not affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4

## Remediation

Refer to the advisory for fix availability.