CVE-2026-6131
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA vulnerability was found in Totolink A7100RU 7.4cu.2313_b20191024. Affected by this vulnerability is the function setTracerouteCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument command results in os command injection. The attack may be launched remotely. The exploit has been made public and could be used.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceOS command injection vulnerability in Totolink A7100RU router's CGI handler (cstecgi.cgi). The setTracerouteCfg function fails to properly sanitize user input passed to the command argument, allowing remote attackers to execute arbitrary operating system commands via crafted HTTP requests.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the router modelAccess the router's web interface or check the device label to confirm it is a Totolink A7100RU. Alternatively, use nmap or inspect HTTP headers/HTML source for model identification.Affected if The device is NOT a Totolink A7100RU router.
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Check the firmware versionLog into the router web interface and navigate to the System or Status page to view the firmware version. Compare this against any Totolink firmware releases that address CVE-2026-6131.Affected if The firmware version has not been patched to address the command injection in setTracerouteCfg.
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Verify the vulnerable CGI binary existsAttempt to access https://[router-ip]/cgi-bin/cstecgi.cgi via HTTP request. A valid response indicates the binary is present.Affected if The /cgi-bin/cstecgi.cgi binary is present and running on the device.
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Confirm remote administration is enabledCheck the router web interface under Administration or Remote Management settings to see if remote access (HTTP/HTTPS on WAN) is enabled. Alternatively, scan the WAN IP for open ports 80/443.Affected if Remote administration or web management interface is accessible from the WAN/Internet.
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Inspect for signs of command injectionReview router logs or network traffic for suspicious entries containing traceroute-related requests to /cgi-bin/cstecgi.cgi with unexpected characters (like ;, |, or backticks) in parameters.Affected if Unexplained commands or suspicious patterns appear in logs related to the CGI endpoint.
A user is affected if they own a Totolink A7100RU router with the vulnerable CGI binary present and remote administration enabled, allowing unauthenticated attackers to inject commands via the setTracerouteCfg function.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply vendor firmware patch when available; until then, restrict network access to the device's management interface or disable the traceroute functionality if possible.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-6131 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-6131 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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