High severity · published Oct 16, 2026
CVE-2026-109588
Numeric truncation in the MPU buffer authorization check in FreeRTOS-Kernel
8.8
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 5% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FR
FreeRTOS-Kernel · FreeRTOS
11.3.0 through 11.3.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-109588
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-109588
aws.amazon.com
https://aws.amazon.com/security/security-bulletins/2026-138-aws/
github.com
https://github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V11.3.2
github.com
https://github.com/FreeRTOS/FreeRTOS-Kernel/security/advisories/GHSA-qf4j-6f5j-876g
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