CVE-2026-51681: Critical severity TOTOLINK T6 vulnerability
Published Aug 31, 2026
·Updated
Incorrect access control in the setRemoteCfg function of TOTOLINK T6 4.1.5cu.748B20211015 allows unauthenticated attackers to expose WAN-side administration 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 31, 2026
CVE Published
via MITRE·12:00 AM
Data Sourced
via MITRE·12:00 AM
Description
Data Sourced
via NVD·02:17 PM
DescriptionSeverityWeakness
Frequently Asked Questions
1
What must an attacker be able to reach to exploit this issue?
An attacker must be able to send a crafted POST request to the device's /cgi-bin/cstecgi.cgi endpoint. The issue is described as exploitable without authentication.
2
What is the immediate security impact of successful exploitation?
Successful exploitation can expose WAN-side administration, potentially making the router's administrative interface reachable from the WAN.
3
Which firmware version is identified as affected?
The affected product and firmware identified are TOTOLINK T6 version 4.1.5cu.748_B20211015.