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Vulnerability record · CVE-2026-7426 · published 29 April 2026

CVE-2026-7426: Amazon freertos-plus-tcp out-of-bounds write vulnerability

Amazon · Freertos Plus Tcp

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.

6.1 CVSS 4.0 Medium EPSS 0.40% · top 68.4% CWE-787 · Out-of-bounds write
6.1CVSS 4.0 base score
0.40%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
4References
17 Jun 2026Last modified by NVD

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.

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:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://aws.amazon.com/security/security-bulletins/2026-023-aws/ Vendor Advisory
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6 Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1 Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-97qg-4359-xm3x PatchVendor Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-7426), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.