Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessGain low-privilege local code execution
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DeliveryIdentify secure context allocation API call site
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ExploitPass undersized stack size parameter
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ExecutionTrigger out-of-bounds write in secure-world heap
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PersistCorrupt heap metadata in TrustZone secure partition
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ImpactUndermine secure-world integrity or availability
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Bounds checking, write limits
MITRE ATT&CK
2 techniques across 2 tactics: Execution, Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires local code execution on the target device with at least low-privilege access (PR:L per the CVSS 4.0 vector), meaning the attacker must already be able to invoke the FreeRTOS secure context allocation API or influence a task that does. The vulnerable code path is only reachable on ARM Cortex-M targets where TrustZone secure context support is compiled in and actively used; embedded systems not using TrustZone secure partitioning are not exposed to this code path. No network access, user interaction, or elevated privileges are required beyond local task execution. Exploitation is further constrained to devices running FreeRTOS-Kernel versions 10.2.0 through 11.3.0. |
| Impact | The CVSS 4.0 vector (AV:L/AC:L/AT:N/PR:L/UI:N) establishes that exploitation requires local access with low privileges and no special attack preconditions beyond having code execution on the device. The subsequent-system impact metrics SI:H and SA:H reflect the high-severity consequence of corrupting the TrustZone secure partition's heap - undermining the integrity and availability of the secure world, which is a critical security boundary in embedded designs. The VC:H metric on the vulnerable system likely reflects that heap metadata in the secure world can be read or disclosed through the write primitive. No EPSS data was provided in the input, leaving exploitation probability unquantifiable from probabilistic signals alone. The CVE is not listed in CISA KEV and no POC has been identified, so active exploitation is not confirmed. Despite the absence of public exploitation signals, the severity of crossing a TrustZone security boundary from low-privilege normal-world code is significant for any deployment where the secure partition enforces sensitive operations such as cryptographic key storage or secure boot. The patch (V11.3.1) is available and straightforward to apply, making the residual risk primarily a patch-lag concern. |
| Exploit ScenarioDerived | An attacker with low-privilege code execution on a TrustZone-enabled embedded device running FreeRTOS-Kernel 10.2.0-11.3.0 calls the secure context allocation function with a deliberately undersized stack size parameter. The kernel, lacking minimum-size validation, writes heap bookkeeping data past the end of the intended allocation in the secure-world heap, corrupting adjacent metadata. The attacker can leverage this heap corruption to manipulate secure-world memory management, potentially enabling arbitrary write or code execution within the TrustZone secure partition. |
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Alert meAnalysisAIv2 – Aug 21, 2026
Out-of-bounds heap metadata corruption in FreeRTOS-Kernel's TrustZone secure context allocation exposes ARM Cortex-M devices to local privilege escalation across the normal-to-secure world boundary. Versions 10.2.0 through 11.3.0 are affected; an attacker with low-privilege local code execution can supply an undersized stack size parameter that bypasses missing minimum-size validation, triggering a CWE-787 out-of-bounds write into secure-world heap metadata. No public exploit has been identified at time of analysis, and this CVE does not appear in CISA KEV; vendor-released patch V11.3.1 is available.
Earlier versions of this analysis (1)
Heap metadata corruption in FreeRTOS-Kernel versions 10.2.0 through 11.3.0 allows local users with low-privilege task execution to corrupt secure-world (ARM TrustZone) heap structures by supplying an undersized stack size parameter to the secure context allocation API. The root cause is a missing minimum size check (CWE-787, out-of-bounds write) in the kernel's TrustZone secure context path, with the scope change crossing the TrustZone trust boundary elevating the impact beyond the calling context. Reported by Amazon, the flaw is patched in V11.3.1 with no public exploit identified at time of analysis.
RemediationAI
The primary remediation is upgrading FreeRTOS-Kernel to version 11.3.1 or later, available at https://github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V11.3.1 and documented in the AWS security bulletin at https://aws.amazon.com/security/security-bulletins/2026-086-aws/. For deployments where an immediate kernel upgrade is not feasible, a compensating control is to add application-level validation of all stack size arguments before invoking the secure context allocation API, enforcing a minimum value consistent with the kernel's heap bookkeeping requirements; this requires auditing every call site and carries the risk of missed coverage if untrusted callers can reach the API directly. Additionally, restricting normal-world task permissions to prevent untrusted code from invoking secure context allocation reduces exposure, but does not eliminate the underlying vulnerability and may not be architecturally possible in all designs.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
FreeRTOS-Kernel is the core scheduling and memory management engine for FreeRTOS, widely deployed on ARM Cortex-M microcontrollers leveraging TrustZone (ARM Security Extensions). The affected code path is the secure context allocation routine - a mechanism by which normal-world tasks request stack allocations managed within the TrustZone secure partition. CWE-787 (Out-of-bounds Write) identifies the root cause: because no minimum stack size is validated before the allocation proceeds, supplying a value smaller than the minimum required heap bookkeeping structure causes the kernel to write heap metadata past the end of the allocated region. The CPE string cpe:2.3:a:freertos:freertos-kernel:*:*:*:*:*:*:*:* covers all platforms, but the vulnerability is exercisable only where TrustZone secure contexts are actively used. The fix was released in V11.3.1 per the GitHub release tag and the AWS security bulletin.
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Severity by source
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:H/SA:H
Local access with low privileges maps directly from description; scope change reflects cross-domain heap corruption impacting the TrustZone secure partition as a distinct security context.
Primary rating from Vendor (AMZN).
CVSS VectorVendor: AMZN
Lifecycle Timeline
2DescriptionCVE.org
Missing minimum size validation in secure context allocation in FreeRTOS-Kernel before 11.3.1 might allow local users to corrupt secure-world heap metadata via an out-of-bounds write with an undersized stack size parameter. To remediate this issue, users should upgrade to version 11.3.1 or later.
Executive ViewAI
FreeRTOS-Kernel versions 10.2.0-11.3.0 contain a privilege escalation vulnerability affecting ARM Cortex-M devices globally; no public exploit identified at time of analysis, but vulnerability allows local attackers to escalate to secure-world access. This impacts IoT systems, medical devices, and industrial equipment where FreeRTOS serves as the core operating system. Organizations should treat patching as a priority given the kernel-level attack surface and pervasive use in mission-critical embedded systems.
Apply vendor patch: FreeRTOS-Kernel V11.3.1
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.
An issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP),
Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Conne
Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Conne
Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Conne
An issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP),
An issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP),
An issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP),
An issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP),
Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Conne
Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Conne
The kernel in Amazon Web Services FreeRTOS before 10.4.3 has insufficient bounds checking during management of heap memo
The kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in stream_buffer.c for a stream buffer.
EUVD-2026-64017
NVD
CVE.org
EPSS
Vulnrichment
GitHub
Exploit-DB