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.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://aws.amazon.com/security/security-bulletins/2026-022-aws/ Vendor Advisory
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-wrhm-c99p-2p8g Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.2 · amazonNVD modified 2026-10-26 20:10
Affected (CPE criteria) 1
cpe:2.3:a:amazon:freertos-plus-tcp:*:*:*:*:*:*:*:*
References 4
- https://aws.amazon.com/security/security-bulletins/2026-022-aws/ Vendor Advisory
- 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 Release Notes
- https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/security/advisories/GHSA-wrhm-c99p-2p8g Vendor Advisory