CVE-2026-51696
Received Received - Intake

Unauthenticated Access Control Bypass in TOTOLINK T6 Router

Publication date: 2026-08-31

Last updated on: 2026-08-31

Assigner: MITRE

Description
Incorrect access control in the setPortForwardRules function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to expose internal services via sending a crafted POST request to /cgi-bin/cstecgi.cgi.

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Meta Information

Published
2026-08-31
Last Modified
2026-08-31
Generated
2026-08-31
AI Q&A
2026-08-31
EPSS Evaluated
N/A
NVD
CVE-2026-51696
EUVD
EUVD-2026-68591

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 setPortForwardRules function of TOTOLINK T6 firmware version 4.1.5cu.748_B20211015. It allows unauthenticated attackers to expose internal network services by sending a specially crafted POST request to the vulnerable endpoint /cgi-bin/cstecgi.cgi.

Detection Guidance

To detect this vulnerability, monitor network traffic for POST requests to /cgi-bin/cstecgi.cgi with parameters related to setPortForwardRules. Check for unauthenticated access attempts or unusual internal service exposure.

Impact Analysis

An attacker could exploit this to access internal services on your network without authentication. This may lead to further network compromise, data exfiltration, or unauthorized control of connected devices.

Compliance Impact

This vulnerability allows unauthenticated attackers to expose internal services, which could lead to unauthorized access to sensitive data. This may violate data protection requirements under GDPR and HIPAA by enabling data breaches or unauthorized disclosures.

Mitigation Strategies

Immediately update TOTOLINK T6 firmware to the latest version. Disable remote access to the web interface if not required. Block external access to /cgi-bin/cstecgi.cgi via firewall rules.

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