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.
{
"cwe_ids": [
"CWE-191"
],
"cna_assigner": "AMZN",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/7xxx/CVE-2026-7424.json"
}