Affects FreeRTOS, a widely deployed embedded RTOS; allows kernel memory access and privilege escalation across many device fleets.
CVE-2026-109588
FreeRTOS MPU bug allows unprivileged tasks to access privileged kernel memory.
Is CVE-2026-109588 being exploited?
Not confirmed. CVE-2026-109588 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-109588?
CVE-2026-109588 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-109588?
Yes. A fix has been recorded for CVE-2026-109588. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-109588 affect?
CVE-2026-109588 affects FreeRTOS-Kernel v11.3.0, FreeRTOS-Kernel v11.3.1, MPU-enabled builds on Arm Cortex-R82 (Armv8-R AArch64). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-109588?
Upgrade to FreeRTOS-Kernel v11.3.2+ and apply vendor device patches now.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local unprivileged task can read/write privileged kernel memory via stream-buffer syscall, enabling privilege escalation, firmware/data theft, and device compromise.
Immediate action required
- affected>= 11.3.0 and <= 11.3.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.