Unauthenticated LED changes via missing CGI authentication
Published Aug 31, 2026 · Updated Aug 31, 2026
Incorrect access control in TOTOLINK T6 4.1.5cu.748_B20211015 allows remote attackers to modify LED behavior via a crafted POST request. The setLedCfg handler in web_cste/cgi-bin/cstecgi.cgi processes topicurl=setLedCfg and an attacker-controlled enable parameter without requiring authentication. Network reachability to the management CGI is sufficient; no credentials or user interaction are required, and the demonstrated consequence is limited to changing LED behavior.
Summary
What happened
Incorrect access control in TOTOLINK T6 4.1.5cu.748_B20211015 allows remote attackers to modify LED behavior via a crafted POST request. The setLedCfg handler in web_cste/cgi-bin/cstecgi.cgi processes topicurl=setLedCfg and an attacker-controlled enable parameter without requiring authentication. Network reachability to the management CGI is sufficient; no credentials or user interaction are required, and the demonstrated consequence is limited to changing LED behavior.
The record
- CVE
- CVE-2026-51680
- Published
- Aug 31, 2026
- Updated
- Aug 31, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-284, T1565.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 31, 2026CVE publishedPublication date reported by the CVE source.
- Aug 31, 2026Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
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Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- setLedCfg unauthenticated POST payloadproof of concept · unverified
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Technologies
Your stack
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