CVE-2026-7424: Amazon Freertos-Plus-TCP

High severity, CVSS 8.1. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Amazon Freertos-Plus-TCP: from 4.0.0, before 4.2.6 (fixed in 4.2.6); from 4.3.0, before 4.4.1 (fixed in 4.4.1)

Published 2026-04-29. Last modified 2026-06-17.