CVE-2026-51770
Received Received - Intake

Incorrect Access Control in TOTOLINK T6 Firmware

Publication date: 2026-09-01

Last updated on: 2026-09-01

Assigner: MITRE

Description
Incorrect access control in the sendToMasterQosConfig function of TOTOLINK T6 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..

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Meta Information

Published
2026-09-01
Last Modified
2026-09-01
Generated
2026-09-01
AI Q&A
2026-09-01
EPSS Evaluated
N/A
NVD
CVE-2026-51770
EUVD
EUVD-2026-69380

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
totolink t6 4.1.5cu.748_b20211015

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability is an incorrect access control issue in the TOTOLINK T6 router firmware version 4.1.5cu.748_B20211015. It exists in the sendToMasterQosConfig function where unauthenticated attackers can send crafted MQTT messages to the cs_broker component. This allows them to forward malicious QoS settings to the master device without proper authentication.

Impact Analysis

If exploited, this vulnerability could allow attackers to manipulate network traffic prioritization by injecting unauthorized QoS settings. This might lead to degraded network performance for legitimate users or enable man-in-the-middle attacks to intercept sensitive data.

Compliance Impact

This vulnerability allows unauthenticated attackers to manipulate QoS settings via crafted MQTT messages, potentially leading to unauthorized access or data exfiltration. Such unauthorized access could violate data protection principles under GDPR (e.g., integrity and confidentiality) and HIPAA (e.g., safeguarding protected health information).

Mitigation Strategies

Update TOTOLINK T6 firmware to the latest version to address the incorrect access control in sendToMasterQosConfig. Disable MQTT message handling for the cs_broker component if not required. Restrict network access to the device to trusted sources only.

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