CVE-2026-7424
Severity CVSS v4.0:
HIGH
Type:
CWE-191
Integer Underflow (Wrap or Wraparound)
Publication date:
29/04/2026
Last modified:
04/05/2026
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&#39;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.<br />
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The issue is present whenever DHCPv6 is enabled.<br />
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To mitigate this issue, users should upgrade to version V4.2.6 or V4.4.1 or newer.
Impact
Base Score 4.0
7.20
Severity 4.0
HIGH
Base Score 3.x
8.10
Severity 3.x
HIGH
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:* | 4.0.0 (including) | 4.2.6 (excluding) |
| cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:* | 4.3.0 (including) | 4.4.1 (excluding) |
To consult the complete list of CPE names with products and versions, see this page



