CVE-2026-7426 PUBLISHED

Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP

Assigner: AMZN
Reserved: 29.04.2026 Published: 29.04.2026 Updated: 29.04.2026

Insufficient validation of the prefix length field in IPv6 Router Advertisement processing in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause memory corruption by sending a crafted Router Advertisement with a prefix length value exceeding the maximum valid length, resulting in a heap buffer overflow. Users processing IPv4 RA only are not impacted.

To mitigate this issue, users should upgrade to the fixed version when available.

CVSS Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CVSS Score: 8.1

Attack Vector	Adjacent Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 6.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Adjacent	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	AWS
Product	FreeRTOS-Plus-TCP
Versions	Default: unaffected affected from 4.0.0 to 4.2.6 (excl.) affected from 4.3.0 to 4.4.1 (excl.) Version 4.2.6 is unaffected Version 4.4.1 is unaffected

CVE-2026-7426 PUBLISHED

Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP

Metrics

Product Status

References

Problem Types

Impacts