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Vulnerability record · CVE-2026-77236 · published 21 August 2026

CVE-2026-77236: Amazon freertos out-of-bounds write vulnerability

Amazon · Freertos

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.

8.3 CVSS 4.0 High EPSS 0.16% · top 95.4% CWE-787 · Out-of-bounds write
8.3CVSS 4.0 base score
0.16%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
3References
25 Aug 2026Last modified by NVD

Description

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.

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://aws.amazon.com/security/security-bulletins/2026-086-aws/ Vendor Advisory
https://github.com/FreeRTOS/FreeRTOS-Kernel/releases/tag/V11.3.1 Release Notes
https://github.com/FreeRTOS/FreeRTOS-Kernel/security/advisories/GHSA-vq2f-9qj3-jj2m Vendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2021-32020Amazon freertos memory buffer overflow vulnerabilityThe kernel in Amazon Web Services FreeRTOS before 10.4.3 has insufficient bounds checking during management of heap memory.EPSS 1.3%9.8CVE-2021-31571Amazon freertos integer overflow vulnerabilityThe kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in queue.c for queue creation.EPSS 1.4%9.8CVE-2021-31572Amazon freertos integer overflow vulnerabilityThe kernel in Amazon Web Services FreeRTOS before 10.4.3 has an integer overflow in stream_buffer.c for a stream buffer.EPSS 1.4%9.3CVE-2026-77234Amazon freertos incorrect authorization vulnerabilityImproper input validation in FreeRTOS-Kernel before 11.3.1 might allow an unprivileged task on MPU-enabled ports to execute code in privileged kernel…EPSS 0.17%8.3CVE-2026-77235Amazon freertos use after free vulnerabilityMissing privilege verification in the secure context cleanup handler in FreeRTOS-Kernel before 11.3.1 might allow local users to cause a use-after-fr…EPSS 0.16%8.2CVE-2026-77237Amazon freertos out-of-bounds read vulnerabilityMissing queue-set type validation in xQueueAddToSet() in the FreeRTOS-Kernel before 11.3.1 might allow an unprivileged task on MPU-enabled ports with…EPSS 0.18%8.1CVE-2018-16601Amazon web services freertos vulnerabilityAn issue was discovered in Amazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Connect…EPSS 4.2%8.1CVE-2018-16525Amazon web services freertos vulnerabilityAmazon Web Services (AWS) FreeRTOS through 1.3.1, FreeRTOS up to V10.0.1 (with FreeRTOS+TCP), and WITTENSTEIN WHIS Connect middleware TCP/IP componen…EPSS 4.4%

Source: NIST National Vulnerability Database (record CVE-2026-77236), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.