CVE-2026-6121
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 flaw has been found in Tenda F451 1.0.0.7. Affected by this vulnerability is the function WrlclientSet of the file /goform/WrlclientSet of the component httpd. This manipulation of the argument GO causes stack-based buffer overflow. The attack may be initiated remotely. The exploit has been published and may 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 · high confidenceA stack-based buffer overflow vulnerability exists in the Tenda F451 router firmware (version 1.0.0.7) within the httpd component's /goform/WrlclientSet function. The 'GO' parameter is not properly validated before being copied to a fixed-size stack buffer, allowing an attacker to overwrite return addresses and potentially achieve remote code execution by sending specially crafted HTTP requests.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data= 1.0.0.7CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/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 the router modelAccess the router admin panel (typically at 192.168.0.1 or 192.168.1.1) and check the device information page, or inspect the device label for the model numberAffected if The device is not a Tenda F451 model - if it is a different model, this CVE does not apply
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Check the firmware versionIn the router admin panel, navigate to System Settings or Firmware Upgrade page to view the current firmware version, or use tools like binwalk to extract version info from a firmware image if availableAffected if The firmware version is not exactly 1.0.0.7 - only version 1.0.0.7 is listed as affected
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Verify httpd service is runningAccess the router via SSH or telnet if enabled, then run 'ps' or check process list to confirm the httpd binary is actively runningAffected if The httpd service is not running - the vulnerability exists in the httpd component, so if the service is disabled the attack surface is reduced
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Confirm the /goform/WrlclientSet endpoint existsSend an HTTP GET or POST request to http://[router-ip]/goform/WrlclientSet and check for a valid HTTP response (not a 404 error)Affected if The endpoint returns a valid response (rather than 404) - the vulnerability only exists when this function is present in the httpd binary
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Test the GO parameter for overflow conditionSend a crafted HTTP POST request to /goform/WrlclientSet with an abnormally long string in the 'GO' parameter (e.g., 1000+ characters) and observe the response or device behaviorAffected if The device accepts a long GO parameter without proper bounds checking - the vulnerability allows overflow when oversized input is copied to a fixed-size stack buffer
A user is affected if they are running Tenda F451 firmware version 1.0.0.7 with the httpd service active and the /goform/WrlclientSet endpoint accessible, as this specific combination exposes the stack buffer overflow in the GO parameter handling.
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 dataIf the vendor does not provide a firmware update, network-level filtering to restrict access to the affected httpd service is recommended, or consider replacing the end-of-life device with a actively supported model.
- Consultation4.0 h
- Implementation16.0 h
- Testing8.0 h
- Review / QA4.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-6121 — 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-2026-6121 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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