Integer Underflow Vulnerability in FreeRTOS Product by Amazon
CVE-2026-7424

7.2HIGH

Key Information:

Vendor

Aws

Status
Freertos-plus-tcp
Vendor
CVE Published:
29 April 2026

What is CVE-2026-7424?

The vulnerability exists due to an integer underflow in the DHCPv6 sub-option parser within FreeRTOS-Plus-TCP, affecting versions prior to V4.4.1 and V4.2.6. When DHCPv6 is enabled, an attacker on an adjacent network can exploit this flaw by sending a specially crafted DHCPv6 packet. This may result in corruption of the device's IPv6 address assignment, DNS configuration, and lease times. Moreover, it can lead to denial of service by freezing the IP task, thus requiring a hardware reset to recover. To address this vulnerability, it is critical for users to upgrade to at least version V4.2.6 or V4.4.1.

Affected Version(s)

FreeRTOS-Plus-TCP 4.0.0 < 4.2.6

FreeRTOS-Plus-TCP 4.3.0 < 4.4.1

FreeRTOS-Plus-TCP 4.2.6

References

https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/ta...
patch
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/ta...
patch
https://aws.amazon.com/security/security-bulletins/2026-0...
vendor-advisory

CVSS V4

Score:
7.2
Severity:
HIGH
Confidentiality:
None
Integrity:
High
Availability:
High
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.