High severity · published Apr 29, 2026
CVE-2026-7424
Integer Underflow in DHCPv6 Sub-Option Parser in FreeRTOS-Plus-TCP
8.1
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 13% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FR
FreeRTOS-Plus-TCP · AWS
4.0.0 before 4.2.6; 4.3.0 before 4.4.1 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-7424
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-7424
Vendor Advisory
https://aws.amazon.com/security/security-bulletins/2026-022-aws/
Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6
Release Notes
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1
Vendor Advisory
https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-wrhm-c99p-2p8g
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