CVE-2026-7426
Out-of-Bounds Write via Unsanitized Prefix Length in Router Advertisement Processing in FreeRTOS-Plus-TCP
Description
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.
INFO
Published Date :
April 29, 2026, 8:16 p.m.
Last Modified :
April 29, 2026, 8:16 p.m.
Remotely Exploit :
No
Source :
ff89ba41-3aa1-4d27-914a-91399e9639e5
Affected Products
The following products are affected by CVE-2026-7426
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | ff89ba41-3aa1-4d27-914a-91399e9639e5 | ||||
| CVSS 4.0 | MEDIUM | ff89ba41-3aa1-4d27-914a-91399e9639e5 | ||||
| CVSS 4.0 | MEDIUM | ff89ba41-3aa1-4d27-914a-91399e9639e5 |
Solution
- Upgrade FreeRTOS-Plus-TCP to a fixed version when available.
- Ensure IPv6 Router Advertisements are processed correctly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-7426.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-7426 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-7426
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-7426 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-7426 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by ff89ba41-3aa1-4d27-914a-91399e9639e5
Apr. 29, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H Added CWE CWE-787 Added Reference https://aws.amazon.com/security/security-bulletins/2026-023-aws/ Added Reference https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.2.6 Added Reference https://github.com/FreeRTOS/FreeRTOS-Plus-TCP/releases/tag/V4.4.1