Published Oct 16, 2026Sources checked Oct 21, 2026
8.8HIGHCVSS out of 10
What this means
Review the available evidence
CVE-2026-109588 and is rated High severity with a CVSS score of 8.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CISA KEVNot listedBased on the latest collected catalog
EPSS0.1%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-109588?
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.