CVE-2026-7424

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.