Home/CVE/Insufficient packet validation in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to bypass
CVE

CVE-2026-7422

Insufficient packet validation in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to bypass

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.

MEDIUM · CVSS 6.5 EPSS 0.00041
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-290Authentication Bypass by Spoofing
▤

Affected Products & Versions

2
amazon freertos-plus-tcp>= 4.0.0 and < 4.2.6
amazon freertos-plus-tcp>= 4.3.0 and < 4.4.1
▣

Scoring & Timeline

6.5
MEDIUM · CVSS v3.1 · ff89ba41-3aa1-4d27-914a-91399e9639e5
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD29 Apr 2026 · 07:16 PM
CVSS VectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

1
aws-security2026-021-aws
🔗

References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://aws.amazon.com/security/security-bulletins/2026-021-aws/Vendor Advisory
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-jpw4-6h59-62w9PatchVendor Advisory
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