CVE-2026-7424

HIGH

Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP

Title source: cna

Description

Integer underflow in the DHCPv6 sub-option parser in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network actor to corrupt the device's IPv6 address assignment, DNS configuration, and lease times, and to cause a denial of service (permanent IP task freeze requiring hardware reset) by sending a single crafted DHCPv6 packet. The issue is present whenever DHCPv6 is enabled. To mitigate this issue, users should upgrade to version V4.2.6 or V4.4.1 or newer.

References (4)

[Patch] https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1

[Patch] https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6

[Vendor Advisory] https://aws.amazon.com/security/security-bulletins/2026-022-aws/

[Third Party Advisory] https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-wrhm-c99p-2p8g

Scores

CVSS v3 8.1

EPSS 0.0001

EPSS Percentile 1.6%

Attack Vector ADJACENT_NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-191

Status published

Products (4)

AWS/FreeRTOS-Plus-TCP 4.0.0 - 4.2.6

AWS/FreeRTOS-Plus-TCP 4.2.6

AWS/FreeRTOS-Plus-TCP 4.3.0 - 4.4.1

AWS/FreeRTOS-Plus-TCP 4.4.1

Published Apr 29, 2026

Tracked Since Apr 30, 2026