CVE-2026-7422: MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing
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 Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-7422?
The severity of CVE-2026-7422 is considered high due to its potential exploitation by adjacent network actors.
How do I fix CVE-2026-7422?
To fix CVE-2026-7422, update FreeRTOS-Plus-TCP to versions 4.2.6 or 4.4.1 or later.
Who is affected by CVE-2026-7422?
CVE-2026-7422 affects FreeRTOS-Plus-TCP versions prior to 4.2.6 and 4.4.1.
What type of vulnerability is CVE-2026-7422?
CVE-2026-7422 is a MAC Address Validation Bypass vulnerability in FreeRTOS-Plus-TCP.
What can an attacker do with CVE-2026-7422?
An attacker can bypass checksum and minimum-size validation by spoofing the Ethernet source MAC address.