# CVE-2026-7422: MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing

> CVE-2026-7422: MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing. CVSS 6.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-7422
Last updated: 2026-06-17T11:02:24Z

- Published: 2026-04-29 18:35 UTC · Updated: 2026-06-17 11:02 UTC · Assigner: AMZN
- CVSS: 6.5 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS: 0.18%, 7th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-290

## 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.

## Affected vendors and products

- AWS: FreeRTOS-Plus-TCP

## Tracked companies

- [Amazon Web Services](https://rewindex.com/company/aws.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-7422)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-7422)
- [https://aws.amazon.com/security/security-bulletins/2026-021-aws/](https://aws.amazon.com/security/security-bulletins/2026-021-aws/)
- [https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6](https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6)
- [https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1](https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1)
- [https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-jpw4-6h59-62w9](https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-jpw4-6h59-62w9)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-7422 · Markdown: https://rewindex.com/cve/CVE-2026-7422.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-7422 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:09:16.034Z