CVE-2026-51695: TOTOLINK T6 vulnerability

Published Aug 31, 2026
·
Updated

Incorrect access control in the setDdnsCfg function of TOTOLINK T6 4.1.5cu.748B20211015 allows unauthenticated attackers to alter dynamic DNS state 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

Frequently Asked Questions

1

Which deployments are exposed?

TOTOLINK T6 devices running firmware version 4.1.5cu.748_B20211015 are identified as affected. The vulnerable functionality is reachable through the device's CGI endpoint.

2

Does exploitation require authentication?

No. An unauthenticated attacker can alter dynamic DNS state by sending a crafted POST request to /cgi-bin/cstecgi.cgi targeting the setDdnsCfg function.

3

What configuration change should defenders look for when investigating possible exploitation?

Review the router's dynamic DNS configuration and state for unauthorized changes. The reported impact is alteration of dynamic DNS settings or state.

Contact

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