CVE-2026-7243
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 identified in Totolink A8000RU 7.1cu.643_b20200521. The affected element is the function setRadvdCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. The manipulation of the argument maxRtrAdvInterval leads to os command injection. It is possible to initiate the attack remotely. The exploit is publicly available and might 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 · moderate confidenceOS command injection vulnerability in Totolink A8000RU router firmware's CGI handler. The setRadvdCfg function in /cgi-bin/cstecgi.cgi fails to properly sanitize the maxRtrAdvInterval parameter before passing it to system commands, allowing remote attackers to execute arbitrary OS commands. The vulnerability is exploitable remotely and public exploits exist.
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 is Totolink A8000RUAccess the router web interface or check the device label/model number. Alternatively, inspect the firmware file or use network discovery to identify the device model.Affected if The device model is Totolink A8000RU and no firmware update has been applied.
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Verify CGI binary existsCheck if /cgi-bin/cstecgi.cgi is present on the device by attempting to access it via the web interface or analyzing the firmware filesystem.Affected if The file /cgi-bin/cstecgi.cgi exists and is accessible on the device.
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Check if radvd service is enabledInspect the router configuration or running services to determine if the radvd daemon is active. This may be visible in the web UI under IPv6/radvd settings or via SSH/telnet access to the device.Affected if The radvd service is enabled and the device has IPv6 routing capabilities.
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Verify web management interface accessibilityDetermine if the router web interface (HTTP/HTTPS on ports 80/443 or custom ports) is reachable from the network. The vulnerability is triggered via CGI requests to cstecgi.cgi.Affected if The web management interface is accessible from untrusted networks.
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Compare firmware version to unaffected releasesCheck the current firmware version in the router web UI (typically under Status or System menu) or via firmware extraction. Since no specific version ranges are provided, treat any unpatched A8000RU firmware as potentially affected.Affected if The installed firmware version does not include the vendor patch for this command injection vulnerability.
The device is affected if it is a Totolink A8000RU with the vulnerable CGI binary present, radvd service enabled, and web interface accessible without the vendor security patch applied.
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 update when available. Until then, disable remote administration interfaces or restrict access to trusted networks to mitigate remote exploitation risk.
- Consultation3.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-7243 — 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-2026-7243 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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