Amazon FreeRTOS-Kernel: Missing type validation in queue-set selection
Summary
FreeRTOS-Kernel before V11.3.3 does not fully validate the kernel object type in the queue-set selection system call on MPU-enabled ports with queue sets enabled. A local task with low privileges can write attacker-controlled data beyond the intended destination on the privileged kernel stack, affecting privileged memory across the MPU isolation boundary. The attacker must already be able to run code as a task on the device.
Affected
- FreeRTOS-Kernel 7.4.0 up to and including 11.3.2
- Only MPU-enabled ports with queue sets enabled (configUSE_QUEUE_SETS=1)
- Builds without queue sets are not affected
Fixed in
- FreeRTOS-Kernel V11.3.3 or later
- Rebuild and reflash affected firmware
- Forked or derivative code must also include the fix
Workaround
- No vendor workaround beyond upgrading. Builds without queue sets are not affected.
- Disabling configUSE_QUEUE_SETS would avoid the vulnerable code path, but this is not a vendor instruction and may break applications that use queue sets. Test first.
Exploitation
- CISA SSVC assessment: exploitation none, automatable no, technical impact partial.
- No confirmed in-the-wild exploitation known. Not listed in CISA KEV in the sources checked.
- Public proof-of-concept status conflicts between sources and is unverified.
Our recommendation
- Inventory devices that embed FreeRTOS and check the kernel version and whether queue sets are used.
- Ask device vendors for firmware built with V11.3.3 and a delivery timeline.
- Until patched, document interim mitigations and prioritise devices that run third-party tasks or are reachable from the network.
- Monitor the GitHub advisory and vendor security bulletins.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- AWS Security Bulletin 2026-158-AWS aws.amazon.com
- FreeRTOS-Kernel GitHub Security Advisory GHSA-56j9-g43f-8g6v github.com
- FreeRTOS-Kernel Release V11.3.3 github.com
- VulDB CVE-2026-119086 vuldb.com
- OffSeq Threat Radar CVE-2026-119086 radar.offseq.com
- Strix CVE-2026-119086 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 14:33.
Original description (NVD)
Missing queue-set type validation in the queue-set selection system call in FreeRTOS-Kernel before V11.3.3 on MPU-enabled ports with queue sets enabled allows a local unprivileged task to write actor-controlled data beyond a pointer-sized object on the privileged kernel stack, affecting privileged memory across the MPU isolation boundary. To remediate this issue, users should upgrade to FreeRTOS-Kernel V11.3.3, rebuild, and reflash affected firmware. Builds that do not enable queue sets are not affected.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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