Command Injection Vulnerability in Zbtlink Firmware Products
CVE-2026-74233

9.3CRITICAL

Key Information:

Vendor

Zbtlink

Status
We1326
We2426-c
We357
We5926
Vendor
CVE Published:
27 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-74233?

A security flaw in the Zbtlink firmware for multiple wireless devices allows remote attackers to exploit the infosrvd service via crafted UDP packets. This vulnerability bypasses authentication mechanisms, as it employs a hardcoded salt, enabling unprivileged users to execute arbitrary commands as root. As a result, devices running affected firmware versions are at significant risk of unauthorized access and potential system compromise.

Affected Version(s)

CTN720-W1 19.1101

LF-1541 19.1101

MT7620N 19.1101

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-74233 - Proof of Concept

References

http://vulncheck.com/blog/zbt-darklantern-speakingstone
technical-descriptionexploit
https://www.vulncheck.com/advisories/zbtlink-mqwrt-infosr...
third-party-advisory

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Jacob Baines of VulnCheck
.