AWS FreeRTOS-Plus-TCP up to 4.2.5/4.4.0 Router Advertisement length out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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7.0$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in AWS FreeRTOS-Plus-TCP up to 4.2.5/4.4.0. This affects an unknown part of the component Router Advertisement Handler. Executing a manipulation of the argument length can lead to out-of-bounds write. This vulnerability appears as CVE-2026-7426. The attacker needs to be present on the local network. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in AWS FreeRTOS-Plus-TCP up to 4.2.5/4.4.0. This vulnerability affects some unknown functionality of the component Router Advertisement Handler. The manipulation of the argument length with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-7426 since 04/29/2026. The exploitation appears to be easy. The attack can only be initiated within the local network. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

Upgrading to version 4.2.6 or 4.4.1 eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-26284). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.2
VulDB Meta Temp Score: 7.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.1
CNA Vector (AMZN): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: FreeRTOS-Plus-TCP 4.2.6/4.4.1

Timelineinfo

04/29/2026 CVE reserved
04/30/2026 +1 days Advisory disclosed
04/30/2026 +0 days VulDB entry created
04/30/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: GHSA-97qg-4359-xm3x
Status: Confirmed

CVE: CVE-2026-7426 (🔒)
GCVE (CVE): GCVE-0-2026-7426
GCVE (VulDB): GCVE-100-360208
EUVD: 🔒

Entryinfo

Created: 04/30/2026 06:36
Updated: 04/30/2026 08:36
Changes: 04/30/2026 06:36 (79), 04/30/2026 08:36 (1)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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