CVE-2026-109588: freertos freertos-kernel Out-of-bounds Read

Vulnerability summary

CVE-2026-109588 is a critical (CVSS 9.3) Out-of-bounds Read vulnerability in freertos freertos-kernel. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.7% of scored vulnerabilities.

Timeline

1. 16-10-2026
   PublishedVulnerability first disclosed.
2. 16-10-2026
   Last modifiedVulnerability information updated.

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.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.
• CWE-197Numeric Truncation ErrorTruncation errors occur when a primitive is cast to a primitive of a smaller size and data is lost in the conversion.
• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.