---
id: CVE-2026-92853
title: >-
  Out-of-bounds Read via a Zero-length TLS 1.3 Certificate Message in NetX
  Secure
summary: >-
  The TLS 1.3 Certificate-message parser in NetX Secure decrements the message
  length to skip a context byte without first establishing that the message has
  a byte to skip. A zero-length Certificate message therefore wraps the unsigned
  len…
severity: high
cvss: 8.7
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-125
  - CWE-191
vendor: Eclipse Foundation
product: NetX Duo
affected:
  - netx_duo <= 6.5.1.202602
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-20T17:02:10.102886Z'
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T17:02:19.980Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-92853'
references:
  - url: >-
      https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-893m-9g4r-4992
tags:
  - cve.org
ingestedAt: '2026-10-20T16:10:53.331Z'
---

## Overview

The TLS 1.3 Certificate-message parser in NetX Secure decrements the message length to skip a context byte without first establishing that the message has a byte to skip. A zero-length Certificate message therefore wraps the unsigned length to `0xFFFFFFFF`, which makes the bounds check that follows vacuous and sends the parser reading past the session packet buffer.



The trigger is a four-byte handshake header and requires no cryptographic validity. It is reachable pre-authentication.

## Affected

- `netx_duo <= 6.5.1.202602`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.