---
id: CVE-2026-66279
title: Dis-connect vulnerability in Connect Stack
summary: >-
  In Connect SDK 4.3.1 and earlier and Flex SDK 3.7.7 and earlier, a message
  with invalid security settings may bypass authentication resulting in network
  disruption. This vulnerability does not allow an attacker to gain the Network
  Key or…
severity: high
cvss: 7.2
cvssVector: 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-940
vendor: Silicon Labs
product: Connect SDK
affected:
  - connect_sdk >= 4.0.0 <= 4.3.1
  - connect_sdk <= 3.7.7
published: '2026-10-22'
updated: '2026-10-22'
sourceUpdated: '2026-10-22T16:01:08.434Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-66279'
references:
  - url: >-
      https://github.com/SiliconLabsSoftware/docs-security-advisories/blob/main/Advisories/500-599/A-00000588.md
  - url: 'https://github.com/SiliconLabsSoftware/sisdk-release/'
tags:
  - cve.org
ingestedAt: '2026-10-22T22:00:50.342Z'
---

## Overview

In Connect SDK 4.3.1 and earlier and Flex SDK 3.7.7 and earlier, a message with invalid security settings may bypass authentication resulting in network disruption. This vulnerability does not allow an attacker to gain the Network Key or otherwise break confidentiality.

## Affected

- `connect_sdk >= 4.0.0 <= 4.3.1`
- `connect_sdk <= 3.7.7`

## Remediation

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