CVE-2026-9531
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 weakness has been identified in Totolink CA750-PoE 6.2c.510. Impacted is the function setUpgradeUboot of the file /cgi-bin/cstecgi.cgi of the component Setting Handler. This manipulation of the argument FileName causes os command injection. The attack is possible to be carried out remotely. The exploit has been made available to the public and could be used for attacks.
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 CA750-PoE router firmware 6.2c.510. The setUpgradeUboot function in /cgi-bin/cstecgi.cgi does not sanitize the FileName parameter before passing it to system() calls, 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
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 CA750-PoEAccess the device web interface or check the device label/marketing materials to verify the exact model numberAffected if Device is not a Totolink CA750-PoE unit
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Identify installed firmware versionLog into the device web interface and navigate to the firmware/version information page, or check via CLI if availableAffected if Firmware version matches 6.2c.510 exactly
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Verify the cstecgi.cgi script is presentAttempt to access the URL /cgi-bin/cstecgi.cgi on the device (e.g., http://[device-ip]/cgi-bin/cstecgi.cgi)Affected if The CGI script responds or is accessible via HTTP/HTTPS
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Check if web interface is network accessibleDetermine if the device HTTP/HTTPS ports are reachable from network segments outside the local LANAffected if The device web interface is exposed to untrusted networks (e.g., WAN, internet)
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Confirm setUpgradeUboot function is exposedSend a request to the CGI endpoint with parameters that would invoke the setUpgradeUboot function (if you have knowledge of the API structure)Affected if The function responds to input without authentication or proper sanitization
You are affected if you have a Totolink CA750-PoE device running firmware version 6.2c.510 with the web interface accessible to network attackers, as the unauthenticated cstecgi.cgi script contains the command injection flaw in the setUpgradeUboot 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 dataRestrict network access to the device's management interface (disable WAN access if enabled), apply vendor firmware patch when available, and monitor for indicators of compromise. If remote administration is not required, disable it entirely.
- Consultation4.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-9531 — 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-2026-9531 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
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