CVE-2026-51765: n/a

This vulnerability arises from improper access control in the recvIndirectMeshInfo function of TOTOLINK T6 firmware version 4.1.5cu.748_B20211015. An unauthenticated attacker can exploit this flaw by sending specially crafted MQTT messages to the cs_broker component, enabling them to insert or replace mesh neighbor records. The vulnerability is classified under CWE-284 (Improper Access Control) and has a CVSS 3.1 base score of 9.8, indicating critical severity with network attack vector, no privileges required, no user interaction, and high impact on confidentiality, integrity, and availability.

Successful exploitation allows unauthenticated attackers to manipulate mesh neighbor records, potentially disrupting mesh network topology, compromising network integrity, and causing denial of service or unauthorized network control. The high CVSS score reflects severe impact on confidentiality, integrity, and availability of the affected device's mesh networking functionality.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or temporary mitigation has been documented at this time. Until a patch is available, restrict network access to MQTT services and monitor for suspicious MQTT traffic targeting the cs_broker component if possible.