CVE-2026-77236 FreeRTOS CVE debrief

Who should care

Users of FreeRTOS-Kernel versions prior to 11.3.1 should be aware of this vulnerability and take steps to upgrade or mitigate the risk. This includes developers and administrators working with FreeRTOS-Kernel in secure environments, as well as operators and security teams responsible for maintaining system security. Those responsible for vulnerability management and platform security should review the CVE record and assess their exposure to this vulnerability. Compensating controls should be considered for exposed systems while remediation is scheduled and verified. Relevant monitoring, detection, and logs should be checked for exposed assets that need extra review. Exceptions should be tracked, and remediated assets should be retested before closing the item, with evidence documented accordingly. Asset inventory and change management processes should also be reviewed to ensure affected systems are properly managed and secured. Rollback and change windows should be considered for remediation efforts. Source tracking and verification of remediation efforts are also crucial to ensure the vulnerability is properly addressed and to prevent potential future exploitation attempts. Security teams should prioritize this vulnerability due to its high severity and potential impact on secure-world heap metadata. They should work closely with affected teams to ensure timely remediation and verify the effectiveness of compensating controls. Additionally, they should monitor for potential exploitation attempts and adjust their detection and response strategies accordingly. By taking these steps, organizations can minimize the risk associated with CVE-2026-77236 and protect their systems from potential attacks. It is essential to review and update affected systems to ensure secure context allocation and prevent potential corruption of secure-world heap metadata. This may involve coordinating with vendors, applying patches, and verifying the effectiveness of remediation efforts. By prioritizing this vulnerability and taking proactive steps to address it, organizations can reduce their risk exposure and protect their systems from potential attacks. The CVE record and related NVD

Technical summary

The CVE-2026-77236 vulnerability in FreeRTOS-Kernel before version 11.3.1 involves a missing minimum size validation in secure context allocation. This issue could potentially allow local users to corrupt secure-world heap metadata via an out-of-bounds write with an undersized stack size parameter. The vulnerability has a CVSS score of 8.3 and is classified as HIGH severity. To remediate this issue, users should upgrade to version 11.3.1 or later. Affected systems should be reviewed and updated to ensure secure context allocation. Monitoring for potential local exploitation attempts is also recommended.

Defensive priority

Upgrade to FreeRTOS-Kernel version 11.3.1 or later to address the missing minimum size validation in secure context allocation.

Recommended defensive actions

• Upgrade to FreeRTOS-Kernel version 11.3.1 or later
• Review and update affected systems to ensure secure context allocation
• Monitor for potential local exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE-2026-77236 record indicates a high-severity vulnerability in FreeRTOS-Kernel before version 11.3.1, with a CVSS score of 8.3. The issue involves missing minimum size validation in secure context allocation, potentially allowing local users to corrupt secure-world heap metadata via an out-of-bounds write with an undersized stack size parameter. Evidence is based on official CVE and NVD records, as well as references from Amazon and FreeRTOS GitHub releases.

Official resources