---
id: CVE-2026-106465
title: >-
  The NetX Secure DTLS server sends a HelloVerifyRequest carrying a freshly
  generated cookie, but never checks the cookie a client returns
summary: >-
  The NetX Secure DTLS server sends a HelloVerifyRequest carrying a freshly
  generated cookie, but never checks the cookie a client returns. The
  ClientHello parser copies the client's cookie bytes over the value the server
  issued, and the s…
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:L'
cwe:
  - CWE-290
  - CWE-406
vendor: Eclipse Foundation
product: NetX Duo
affected:
  - netx_duo <= 6.5.2.202603
published: '2026-10-14'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T21:17:18.130'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-106465'
references:
  - url: >-
      https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-7c5f-gmpm-f655
    label: emo@eclipse.org
  - url: 'https://gitlab.eclipse.org/security/cve-assignment/-/work_items/379'
    label: emo@eclipse.org
tags:
  - nvd
  - cve.org
epss: 0.00307
epssPercentile: 0.23336
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T20:14:34.554226Z'
cvssSource: cna
ingestedAt: '2026-10-14T18:47:39.309Z'
---

## Overview

The NetX Secure DTLS server sends a HelloVerifyRequest carrying a freshly generated cookie, but never checks the cookie a client returns. The ClientHello parser copies the client's cookie bytes over the value the server issued, and the server then decides whether the client has been verified from the cookie's length alone. A peer that puts any single cookie byte in its first ClientHello skips the verification exchange entirely, so the server has no return-routability check and completes handshakes for forged source addresses.

## Remediation

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