How severe is CVE-2026-77236?

CVE-2026-77236 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.

Is CVE-2026-77236 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-77236?

CVE-2026-77236 affects Amazon Freertos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-77236?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-77236 published?

CVE-2026-77236 was published on 2026-08-21 and last updated on 2026-08-25.

CVE-2026-77236

CVE-2026-77236 is a high-severity vulnerability in Amazon Freertos with a CVSS 3.x base score of 7.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.3)
CVSS v4: 8.3
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Amazon Freertos
Published: 2026-08-21
Last modified: 2026-08-25

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.

Frequently asked questions

What is CVE-2026-77236?: 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.
How severe is CVE-2026-77236?: CVE-2026-77236 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2026-77236 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-77236?: CVE-2026-77236 affects Amazon Freertos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-77236?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-77236 published?: CVE-2026-77236 was published on 2026-08-21 and last updated on 2026-08-25.

References

Affected products (1)

cpe:2.3:o:amazon:freertos:*:*:*:*:*:*:*:*

More vulnerabilities in Amazon Freertos

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