CVE-2026-7426

Severity CVSS v4.0:

MEDIUM

Type:

CWE-787 Out-of-bounds Write

Publication date:

29/04/2026

Last modified:

04/05/2026

Description

Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.<br /> <br /> <br /> <br /> To mitigate this issue, users should upgrade to the fixed version when available.

Impact

Vector 4.0

CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 6.10 MEDIUM
Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Attack Requirements (AT): Present
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): High
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0

6.10

Severity 4.0

MEDIUM

Vector 3.x

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.10 HIGH
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): High
Availability (A): 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

CVE-2026-7426

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools