CVE-2026-7424 Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP
An attacker can cause a denial of service and corrupt network configuration in FreeRTOS-Plus-TCP devices via a crafted DHCPv6 packet.
- 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-2026-7424?
CVE-2026-7424 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
Integer underflow in the DHCPv6 sub-option parser in FreeRTOS-Plus-TCP before V4.4.1 and V4.2.6 allows an adjacent network actor to corrupt the device's IPv6 address assignment, DNS configuration, and lease times, and to cause a denial of service (permanent IP task freeze requiring hardware reset) by sending a single crafted DHCPv6 packet.
The issue is present whenever DHCPv6 is enabled.
To mitigate this issue, users should upgrade to version V4.2.6 or V4.4.1 or newer.
Weakness: CWE-191
Which versions are affected by CVE-2026-7424?
It affects 1 product.
Products include Amazon Freertos-Plus-Tcp.
How do I fix CVE-2026-7424?
No fix has been published for CVE-2026-7424 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-7424 being exploited?
There is no known exploitation of CVE-2026-7424 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-2026-7422 MAC Address Validation Bypass in FreeRTOS-Plus-TCP IPv4 and IPv6 Packet Processing
- 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-wrhm-c99p-2p8g.