CVE-2026-9457
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. The affected element is the function UploadFirmwareFile of the file /cgi-bin/cstecgi.cgi of the component Web Management Interface. This manipulation of the argument FileName causes os command injection. The attack is possible to be carried out 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's web management interface (cstecgi.cgi). The UploadFirmwareFile function fails to properly sanitize the FileName argument, allowing remote attackers to execute arbitrary OS commands. With CVSS 9.8, this is trivially exploitable remotely without authentication and grants full system compromise.
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 device modelAccess the router's web management interface and check the device information page, or examine the device label/hardware markings for the model numberAffected if The device is not a Totolink A8000RU router
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Check firmware versionLog into the web management interface and navigate to the firmware/version information page, or use the router's status page to display the current firmware versionAffected if The installed firmware version predates any vendor security update for this vulnerability (compare your version to the vendor's release notes)
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Verify web interface accessibilityDetermine if the router's web management interface (ports 80/443) is accessible from untrusted networks by attempting access from an external IP or reviewing firewall rulesAffected if The cstecgi.cgi endpoint is reachable from untrusted/untrusted networks without network segmentation or access controls
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Test cstecgi.cgi availabilitySend an HTTP request to the router's web interface targeting /cstecgi.cgi (or the CGI path used by this device) and observe the responseAffected if The CGI endpoint responds and accepts parameters, indicating the vulnerable interface is active
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Check for compromise indicatorsReview router system logs for unusual CGI requests, particularly those containing shell metacharacters (such as ;, |, `, or $()) in the FileName parameter, or for unexpected firmware upload attemptsAffected if Logs show suspicious requests to UploadFirmwareFile function with abnormal parameter patterns, or if unauthorized configuration changes have occurred
You are affected if you own a Totolink A8000RU router with an unpatched firmware version and the web management interface (specifically cstecgi.cgi) is accessible from your network.
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 dataImmediately restrict or disable the web management interface access from untrusted networks; contact Totolink for firmware patch; if no patch available, consider network isolation or device replacement.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-9457 — 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-2026-9457 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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