CVE-2026-7426

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

6.1CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

8.1CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 15% of CVEs (scores of 2026-10-26)

CWE

CWE-787

Published

2026-04-29

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• amazon:freertos-plus-tcp

References

• https://aws.amazon.com/security/security-bulletins/2026-023-aws/
• https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6
• https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1
• https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-97qg-4359-xm3x

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