CVE-2026-51656: TOTOLINK T6 vulnerability
Published Aug 28, 2026
·Updated
Incorrect access control in the getVpnPassCfg function of TOTOLINK T6 4.1.5cu.748B20211015 allows unauthenticated attackers to obtain VPN pass-through and WAN ping filter settings 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
Frequently Asked Questions
1
What information can an unauthenticated attacker retrieve?
An unauthenticated attacker can obtain the router's VPN pass-through settings and WAN ping filter settings.
2
What access does an attacker need to exploit this issue?
The attacker only needs to be able to send a crafted POST request to the device's /cgi-bin/cstecgi.cgi endpoint; no authentication is required.
3
How can I determine whether a device is exposed?
Check whether the device is a TOTOLINK T6 running firmware version 4.1.5cu.748_B20211015 and whether its web management CGI endpoint is reachable by potential attackers.