CVE-2026-5852
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 A7100RU 7.4cu.2313_b20191024. Affected is the function setIptvCfg of the file /cgi-bin/cstecgi.cgi of the component CGI Handler. This manipulation of the argument igmpVer 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 · high confidenceOS command injection vulnerability in Totolink A7100RU router's CGI handler. The setIptvCfg function in /cgi-bin/cstecgi.cgi fails to sanitize the igmpVer parameter before passing it to system commands, allowing remote attackers to execute arbitrary OS commands with elevated privileges.
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 A7100RUAccess the router's web interface or check the administrative console for the exact model number. Alternatively, inspect HTTP responses or SNMP data that may reveal the device identifier.Affected if The device is a Totolink A7100RU router.
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Verify CGI binary exists and is accessibleAttempt to access the endpoint /cgi-bin/cstecgi.cgi via HTTP or HTTPS. A response (even an error) indicates the CGI handler is present.Affected if The /cgi-bin/cstecgi.cgi endpoint is reachable on the network.
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Check if IPTV configuration feature is exposedSend a request to the CGI endpoint with an action parameter targeting setIptvCfg (or observe which endpoints respond to IPTV-related configuration commands).Affected if The setIptvCfg function is accessible and accepts configuration input.
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Inspect the igmpVer parameter handlingIf IPTV is configurable, examine whether the igmpVer parameter can be modified. Compare the parameter's value to expected valid values (typically numeric such as 2 or 3).Affected if The igmpVer parameter accepts arbitrary string input without validation.
A user is affected if they are running a Totolink A7100RU router with the web interface accessible and the IPTV configuration feature enabled, where the igmpVer parameter in setIptvCfg accepts unsanitized input.
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 if available; otherwise restrict network access to the device's web interface via firewall rules or network segmentation, and monitor for indicators of compromise.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-5852 — 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-2026-5852 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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