---
id: CVE-2026-74233
title: >-
  Zbtlink WE1326, WE357, WE5926, WE5926-WD, WE826-Q, WE826-T2, WE826-WD, WG108,
  and WG3526 firmware 19.1101, Zbtlink WE2426-C firmware 19.1112, Zbtlink
  WE5926-EC_QP firmware 20.0516, Zbtlink WF3526-P firmware 19.051, CTN720-W1,
  LF-1541, an…
summary: >-
  Zbtlink WE1326, WE357, WE5926, WE5926-WD, WE826-Q, WE826-T2, WE826-WD, WG108,
  and WG3526 firmware 19.1101, Zbtlink WE2426-C firmware 19.1112, Zbtlink
  WE5926-EC_QP firmware 20.0516, Zbtlink WF3526-P firmware 19.051, CTN720-W1,
  LF-1541, an…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-78
  - CWE-321
published: '2026-08-27'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:43:32.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74233'
references:
  - url: 'http://vulncheck.com/blog/zbt-darklantern-speakingstone'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/zbtlink-mqwrt-infosrvd-command-injection
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.0337
epssPercentile: 0.88272
ingestedAt: '2026-09-24T20:51:40.234Z'
---

## Overview

Zbtlink WE1326, WE357, WE5926, WE5926-WD, WE826-Q, WE826-T2, WE826-WD, WG108, and WG3526 firmware 19.1101, Zbtlink WE2426-C firmware 19.1112, Zbtlink WE5926-EC_QP firmware 20.0516, Zbtlink WF3526-P firmware 19.051, CTN720-W1, LF-1541, and MT7620N firmware 19.1101, and WRC1 firmware 20.0622 contain an unauthenticated command injection in the infosrvd service (UDP/9992). A remote unauthenticated attacker can send a crafted UDP packet to execute arbitrary commands as root. The service's authentication uses a hardcoded salt and an all-zero wildcard MAC bypass, rendering it ineffective.

## Remediation

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