CVE-2026-7124
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 determined in Totolink A8000RU 7.1cu.643_b20200521. Affected by this vulnerability is the function setIpv6LanCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. Executing a manipulation of the argument addrPrefixLen can lead to os command injection. The attack can be launched remotely. The exploit has been publicly disclosed and may be utilized.
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 · moderate confidenceOS command injection vulnerability in Totolink A8000RU router firmware where the setIpv6LanCfg function in /cgi-bin/cstecgi.cgi does not properly sanitize the addrPrefixLen parameter before passing it to system shell commands, allowing remote attackers to execute arbitrary OS commands.
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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Confirm device model is Totolink A8000RULog into the router web interface or check the device label/marketing materials to verify the exact model numberAffected if Device is not a Totolink A8000RU unit
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Check firmware versionAccess the router web interface (usually at 192.168.0.1 or 192.168.1.1), navigate to System Status or Firmware Upgrade section, and record the firmware version stringAffected if Firmware version is unpatched and predates any vendor security fix
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Verify vulnerable CGI binary existsAttempt to access the file /cgi-bin/cstecgi.cgi on the router (e.g., via HTTP GET request to http://<router-ip>/cgi-bin/cstecgi.cgi). A 200 response or similar indicates the binary exists.Affected if The cstecgi.cgi binary is present and responds to requests
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Check if web management interface is exposed to untrusted networksReview router firewall settings, WAN access controls, or port forwarding rules to determine if TCP ports 80/443 (HTTP/HTTPS) on the WAN interface are open or if remote management is enabledAffected if The router's web interface is accessible from WAN/untrusted networks (not just LAN)
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Confirm setIpv6LanCfg function is reachableSend an HTTP POST request to /cgi-bin/cstecgi.cgi with a JSON payload containing the setIpv6LanCfg action and a test value for addrPrefixLen (e.g., {"topicurl":"setIpv6LanCfg","addrPrefixLen":";echo test"}). A response indicating the command executed or shell output returned confirms the vulnerability.Affected if The addrPrefixLen parameter is not sanitized and allows shell metacharacters to be interpreted
The device is affected if it is a Totolink A8000RU with unpatched firmware, the vulnerable cstecgi.cgi binary is present, and the web management interface is accessible (either locally or remotely) allowing injection through the addrPrefixLen parameter of the setIpv6LanCfg 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, disable remote web management access, restrict administrative interfaces to trusted networks only, or implement network segmentation to limit exposure.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-7124 — 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-2026-7124 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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- Version or environment caveats, and links to real fixes
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