CVE-2026-7422 MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing
An adjacent attacker can bypass packet validation checks by spoofing the source MAC address to match a local endpoint in FreeRTOS-Plus-TCP.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-7422?
CVE-2026-7422 is a high-severity vulnerability in AWS FreeRTOS-Plus-TCP, published on 29 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Weakness: CWE-290
Which versions are affected by CVE-2026-7422?
It affects 1 product.
Products include Amazon Freertos-Plus-Tcp.
How do I fix CVE-2026-7422?
No fix has been published for CVE-2026-7422 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-7422 being exploited?
There is no known exploitation of CVE-2026-7422 in the wild and no public exploit code.
Other vulnerabilities in AWS FreeRTOS-Plus-TCP
- CVE-2024-38373 FreeRTOS-Plus-TCP Buffer Over-Read in DNS Response Parser
- CVE-2026-7424 Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP
- CVE-2026-7426 Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP
- CVE-2026-7423 Integer Underflow in ICMP Echo Reply Processing in FreeRTOS-Plus-TCP
- CVE-2026-7425 Out-of-Bounds Read in Router Advertisement Option Parser in FreeRTOS-Plus-TCP
Sources
Also known as GHSA-jpw4-6h59-62w9.