CVE-2026-7422

MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing

CVSS 7.1 HIGHEPSS 0.2%CWE-290

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 7.1EPSS 0.2%KEV nãoPoC —Patch referenciado

Lifecycle

29 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

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:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Affected products

AWS · FreeRTOS-Plus-TCP

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References

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/V4.4.1 https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-jpw4-6h59-62w9