CVE-2026-51769 Missing authorization in n/a

Critical 9.8 Published Updated

Unauthenticated attackers can restart the cloud update check workflow on TOTOLINK T6 routers by sending crafted MQTT messages, potentially causing service disruption.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-51769?

CVE-2026-51769 is a critical missing authorization vulnerability in n/a, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Incorrect access control in the remoteCloudUpdateCheck function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to restart the cloud update check workflow via sending a crafted MQTT message to the cs_broker component.

Weakness: CWE-284

Which versions are affected by CVE-2026-51769?

How do I fix CVE-2026-51769?

No fix has been published for CVE-2026-51769 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-51769 being exploited?

There is no known exploitation of CVE-2026-51769 in the wild and no public exploit code.

Sources

Also known as GHSA-86c4-6mm3-v64j.

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