---
id: CVE-2026-109588
title: Numeric truncation in the MPU buffer authorization check in FreeRTOS-Kernel
summary: >-
  Numeric truncation of the buffer length in the MPU buffer authorization check
  in FreeRTOS-Kernel V11.3.0 and V11.3.1 on the Arm Cortex-R82 (Armv8-R AArch64)
  MPU port might allow, under certain conditions, an unprivileged task on
  MPU-enab…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-197
  - CWE-787
  - CWE-125
vendor: FreeRTOS
product: FreeRTOS-Kernel
affected:
  - FreeRTOS-Kernel >= 11.3.0 <= 11.3.1
published: '2026-10-16'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T17:18:18.351Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-109588'
references:
  - url: 'https://github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V11.3.2'
  - url: 'https://aws.amazon.com/security/security-bulletins/2026-138-aws/'
  - url: >-
      https://github.com/FreeRTOS/FreeRTOS-Kernel/security/advisories/GHSA-qf4j-6f5j-876g
tags:
  - cve.org
ingestedAt: '2026-10-16T18:43:08.828Z'
---

## Overview

Numeric truncation of the buffer length in the MPU buffer authorization check in FreeRTOS-Kernel V11.3.0 and V11.3.1 on the Arm Cortex-R82 (Armv8-R AArch64) MPU port might allow, under certain conditions, an unprivileged task on MPU-enabled builds to read or write privileged kernel memory beyond the validated buffer window, via a stream buffer system call.



To remediate this issue, users should upgrade to version V11.3.2 or later.

## Affected

- `FreeRTOS-Kernel >= 11.3.0 <= 11.3.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.