CVE-2026-51770: n/a

This vulnerability arises from improper access control in the sendToMasterQosConfig function of TOTOLINK T6 4.1.5cu.748_B20211015. An unauthenticated attacker can exploit this flaw by sending a specially crafted MQTT message to the cs_broker component, enabling them to forward malicious QoS configurations to the master device. The CVSS score of 9.8 indicates a critical severity with network attack vector, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability. No patch or remediation guidance is currently available, and no known exploits in the wild have been reported.

Successful exploitation allows unauthenticated attackers to modify QoS settings on the master device, potentially disrupting network traffic management and causing significant confidentiality, integrity, and availability impacts as indicated by the CVSS score of 9.8.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to MQTT broker components and monitor for suspicious MQTT traffic to mitigate potential exploitation.