CVE-2026-51617: High severity TOTOLINK T6 vulnerability

Published Aug 28, 2026

Updated

Incorrect access control in the getSysStatusCfg function of TOTOLINK T6 4.1.5cu.748B20211015 allows unauthenticated attackers to obtain sensitive information such as operation mode, firmware version, serial number, WAN/LAN IP addresses, WiFi SSID, encryption keys, and connected client statistics via sending a crafted POST request to /cgi-bin/cstecgi.cgi.

Affected Software

1 affected component

TOTOLINK T6=4.1.5cu.748_B20211015

Event History

Aug 28, 2026

CVE Published

via MITRE·12:00 AM

Data Sourced

via MITRE·12:00 AM

Description

Data Sourced

via NVD·08:18 PM

DescriptionSeverityWeakness

Frequently Asked Questions

Who can exploit this issue?

An unauthenticated attacker can exploit it, so no valid router login is required. Any attacker able to send a crafted POST request to the device's CGI endpoint is exposed to this access-control failure.

What information could be disclosed?

The affected function can expose the operation mode, firmware version, serial number, WAN and LAN IP addresses, WiFi SSID, encryption keys, and connected-client statistics.

How can I check whether a device is affected?

Confirm that the device is a TOTOLINK T6 running firmware 4.1.5cu.748_B20211015. The issue concerns unauthenticated access to getSysStatusCfg through /cgi-bin/cstecgi.cgi.