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.



To mitigate this issue, users should upgrade to the fixed version when available.
Published: 2026-04-29
Score: 6 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Mon, 04 May 2026 13:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*

Thu, 30 Apr 2026 08:30:00 +0000

Type Values Removed Values Added
First Time appeared Amazon
Amazon freertos-plus-tcp
Vendors & Products Amazon
Amazon freertos-plus-tcp

Wed, 29 Apr 2026 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 29 Apr 2026 19:00:00 +0000

Type Values Removed Values Added
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. To mitigate this issue, users should upgrade to the fixed version when available.
Title Integer Underflow in ICMP Echo Reply Processing in FreeRTOS-Plus-TCP
Weaknesses CWE-191
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 6, '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'}


Subscriptions

Amazon Freertos-plus-tcp
cve-icon MITRE

Status: PUBLISHED

Assigner: AMZN

Published:

Updated: 2026-04-29T19:08:11.602Z

Reserved: 2026-04-29T14:27:49.474Z

Link: CVE-2026-7423

cve-icon Vulnrichment

Updated: 2026-04-29T19:08:07.142Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-29T19:16:26.617

Modified: 2026-05-04T13:35:00.500

Link: CVE-2026-7423

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-30T08:15:31Z

Weaknesses