by Kastro
Paper/Archive/CVE-2026-109588

CVE-2026-109588

FreeRTOS FreeRTOS-Kernel — Numeric truncation in the MPU buffer authorization check in FreeRTOS-Kernel

EPSS 0.2%CVSS 9.3
critical.is priorityof 100
29
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 4.9.049 × 201.0No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
FreeRTOS-Kernel11.3.0 – 11.3.1–CNA

Scores by source

AMZN (CNA)9.3CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
AMZN (CNA)8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

patchgithub.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V11.3.2advisoryaws.amazon.com/security/security-bulletins/2026-138-awswriteupgithub.com/FreeRTOS/FreeRTOS-Kernel/security/advisories/GHSA-qf4j-6f5j-876g