CVE-2026-7422

Received Received - Intake

Insufficient Packet Validation in FreeRTOS-Plus-TCP

Publication date: 2026-04-29

Last updated on: 2026-05-04

Assigner: AMZN

Description

Insufficient packet validation in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match one of the device's own registered endpoints, because the loopback detection mechanism skips all input validation for packets whose source MAC matches a local endpoint. To mitigate this issue, users should upgrade to the fixed version when available.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-04-29

Last Modified

2026-05-04

Generated

2026-07-27

AI Q&A

2026-04-29

EPSS Evaluated

2026-07-25

NVD

CVE-2026-7422

EUVD

EUVD-2026-26275

Affected Vendors & Products

Vendor	Product	Version / Range
amazon	freertos-plus-tcp	From 4.0.0 (inc) to 4.2.6 (exc)
amazon	freertos-plus-tcp	From 4.3.0 (inc) to 4.4.1 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-290	This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.

Attack-Flow Graph

Executive Summary

This vulnerability is due to insufficient packet validation in FreeRTOS-Plus-TCP versions before V4.2.6 and V4.4.1. An attacker on an adjacent network can bypass all checksum and minimum-size validation by spoofing the Ethernet source MAC address to match one of the device's own registered endpoints. This happens because the loopback detection mechanism skips all input validation for packets whose source MAC address matches a local endpoint.

Detection Guidance

This vulnerability involves an adjacent network actor spoofing the Ethernet source MAC address to match one of the device's own registered endpoints, bypassing checksum and minimum-size validation. Detection would involve monitoring network traffic for packets with source MAC addresses that match local endpoints but exhibit malformed or suspicious packet structures.

Specific commands or tools to detect this vulnerability are not provided in the available resources.

Impact Analysis

The impact of this vulnerability is that an adjacent network actor can send malicious packets that bypass important validation checks, potentially leading to the processing of malformed or harmful network packets. This could result in network disruptions or exploitation of the device's TCP/IP stack.

Compliance Impact

The vulnerability allows an adjacent network actor to bypass checksum and minimum-size validation by spoofing the Ethernet source MAC address, potentially enabling malformed packets to evade security checks.

This could impact data integrity due to the ability to send malformed packets that are not properly validated.

However, there is no direct effect on confidentiality or availability according to the CVSS assessment.

Given the impact on data integrity, organizations subject to standards like GDPR or HIPAA, which require protection of data integrity and security, may need to address this vulnerability to maintain compliance.

Mitigation involves upgrading to fixed versions of FreeRTOS-Plus-TCP, which is necessary to reduce risk and support compliance efforts.

Mitigation Strategies

To mitigate this issue, users should upgrade to the fixed version of FreeRTOS-Plus-TCP when it becomes available.

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