CVE-2026-51769
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk37th percentile - higher than 37% of all known CVEs
Summary
Incorrect access control in the remoteCloudUpdateCheck function of TOTOLINK T6 (version 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.
Risk Assessment
An attacker can repeatedly trigger update checks, potentially causing device overload or unwanted configuration changes.
Recommendation
Restrict access to the cs_broker component and update the TOTOLINK T6 firmware if a patch is available.
Other vulnerabilities in TOTOLINK T6
See all- CVE-2026-51770Critical
Incorrect access control in the sendToMasterQosConfig function of TOTOLINK T6 (version 4.1.5cu.748_B20211015) allows unauthenticated attackers to forward attacker-controlled QoS settings to the master via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51767Critical
Incorrect access control in the recvClearPairCfg function of TOTOLINK T6 (version 4.1.5cu.748_B20211015) allows unauthenticated attackers to reset pairing state and reboot the device via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51765Critical
Incorrect access control in the recvIndirectMeshInfo function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to insert or replace mesh neighbor records via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51764Critical
Incorrect access control in the recvSlaveCloudCheckStatus function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to overwrite cloud-result tracking files via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51763Critical
Incorrect access control in the freeStaClient function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to forcibly disconnect wireless clients via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51762Critical
Incorrect access control in the meshInfoKick function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to kick or clean stale mesh information/state and trigger regeneration of mesh metadata via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51760Critical
Incorrect access control in the informSyncUpgfw function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to mass-trigger firmware update activity across mesh slaves via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51757Critical
Incorrect access control in the meshSlaveUpdate function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to start a firmware download or flash workflow on the slave device via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51754Critical
Incorrect access control in the updateSlaveIpList function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to overwrite the slave IP inventory state via sending a crafted MQTT message to the cs_broker component.
- CVE-2026-51751Critical
Incorrect access control in the delSlaveDevice function of TOTOLINK T6 allows unauthenticated attackers to remove a specified slave device from local mesh management data and reboot the system via a crafted MQTT message to the cs_broker component.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS