What is CVE-2026-77234?

CVE-2026-77234 is a high-severity vulnerability in Amazon Freertos, classified under Incorrect Authorization. CVSS score: 8.8/10. Published 2026-08-21.

How severe is CVE-2026-77234?

High severity. CVSS v3 base score is 8.8 out of 10.

Auth bypass in Amazon Freertos

CVE-2026-77234

Improper input validation in FreeRTOS-Kernel before 11.3.1 might allow an unprivileged task on MPU-enabled ports to execute code in privileged kernel context. To remediate this issue, users should upgrade to version 11.3.1 or later.

Vulnerability class: Broken Access Control

Published 2026-08-21 · last modified 2026-08-27.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (5.7th percentile), scored 2026-10-06.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 5.7% 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: +0.001

Affected products

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (Release Notes, patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory, Vendor Advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (Vendor Advisory, third-party-advisory)

Frequently asked questions

What is CVE-2026-77234?: CVE-2026-77234 is a high-severity vulnerability in Amazon Freertos, classified under Incorrect Authorization. CVSS score: 8.8/10. Published 2026-08-21.
How severe is CVE-2026-77234?: High severity. CVSS v3 base score is 8.8 out of 10.