CVE-2026-7426

Name: CVE-2026-7426
Creator: NVD / NIST
Published: 2026-04-29T20:16:32.143+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.25%

Last modified Jun 17, 2026

CVE-2026-7426 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted. To mitigate this issue, users should upgrade to the fixed version when available.. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

Description

Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted. To mitigate this issue, users should upgrade to the fixed version when available.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

CVSS 4.0

6.1/10

CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/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:X/V:X/RE:X/U:X

EPSS Probability

0.25%

15.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Amazon	Freertos-Plus-Tcp	>= 4.0.0, < 4.2.6
Amazon	Freertos-Plus-Tcp	>= 4.3.0, < 4.4.1

References

https://aws.amazon.com/security/security-bulletins/2026-023-aws/Vendor Advisory
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-97qg-4359-xm3xPatch, Vendor Advisory

Timeline

Published: Apr 29, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-7426?

How severe is CVE-2026-7426?

CVE-2026-7426 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2026-7426?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-7426?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST