Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2026-7423

Severity CVSS v4.0:
MEDIUM
Type:
CWE-191 Integer Underflow (Wrap or Wraparound)
Publication date:
29/04/2026
Last modified:
04/05/2026

Description

Integer underflow in the ICMP and ICMPv6 echo reply handlers in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network user to cause a denial of service (device crash) when outgoing ping support is enabled, because header sizes are subtracted from a packet length field without validating the field is large enough, resulting in a heap out-of-bounds read of up to approximately 65KB.<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:N/VA:H/SC:N/SI:N/SA:N CVSS v4.0 Severity and Metrics:

Base Score: 6.00 MEDIUM
Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/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): None
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): None

Base Score 4.0
6.00
Severity 4.0
MEDIUM
Vector 3.x
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 5.30 MEDIUM
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

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

Base Score 3.x
5.30
Severity 3.x
MEDIUM

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


References to Advisories, Solutions, and Tools