Buffer overflow in Amazon Freertos
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:H.
EPSS exploit prediction
EPSS: 0.002 (4.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 5th percentile — 4.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
Weakness classification (CWE)
References
- ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory, Vendor Advisory)
- ff89ba41-3aa1-4d27-914a-91399e9639e5 (Release Notes, patch)
- ff89ba41-3aa1-4d27-914a-91399e9639e5 (Vendor Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-77236?
- CVE-2026-77236 is a high-severity vulnerability in Amazon Freertos, classified under Out-of-bounds Write. CVSS score: 7.3/10. Published 2026-08-21.
- How severe is CVE-2026-77236?
- High severity. CVSS v3 base score is 7.3 out of 10.