Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-6631

HIGH · 8.8 CVSS v3.1 Published 2026-04-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

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 · unedited
A vulnerability was determined in Tenda F451 1.0.0.7_cn_svn7958. Impacted is the function fromwebExcptypemanFilter of the file /goform/webExcptypemanFilter of the component httpd. Executing a manipulation of the argument page can lead to buffer overflow. The attack may be launched 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 confidence

Buffer overflow vulnerability in Tenda F451 router's httpd component. The fromwebExcptypemanFilter function in /goform/webExcptypemanFilter is vulnerable when processing the 'page' argument, allowing remote attackers to overflow a buffer. The exploit is publicly available and can be launched remotely without authentication.

MitigationApply vendor firmware patch when available; until then, restrict network access to the router's management interface or disable remote administration to reduce attack surface.

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
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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify the router model
    Access the router's web interface or check the device label to confirm it is a Tenda F451 router. Alternatively, check the HTTP Server header in responses or use network enumeration tools to identify the device.
    Affected if The device is a Tenda F451 router.
  2. Check the firmware version
    Log into the router admin panel and navigate to the System or Firmware section to view the installed firmware version. Compare this to any vendor advisories for fixed versions.
    Affected if The firmware version is older than the patched version or no patch is available.
  3. Verify httpd service is running
    Scan the router's IP on common HTTP ports (80, 443, 8080) using a tool like curl or netcat to confirm the httpd service is listening and responding.
    Affected if The httpd service is running and accessible on the network.
  4. Test access to the vulnerable endpoint
    Send an HTTP GET or POST request to http://[router-ip]/goform/webExcptypemanFilter and verify the endpoint responds. Use a tool like curl: curl -v http://[router-ip]/goform/webExcptypemanFilter
    Affected if The endpoint responds with a valid HTTP response, indicating the vulnerable code path exists.
  5. Check if remote administration is enabled
    In the router admin panel, locate the Remote Management or Remote Access settings (often under Advanced or Administration). Verify whether remote access from WAN is permitted.
    Affected if Remote administration is enabled, allowing external attackers to reach the vulnerable endpoint.

A user is affected if they own a Tenda F451 router with the httpd service running, the /goform/webExcptypemanFilter endpoint accessible, and especially if remote administration is enabled, allowing unauthenticated remote exploitation.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware patch when available; until then, restrict network access to the router's management interface or disable remote administration to reduce attack surface.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
25.0 hours of engineering $4,400
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-6631 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-6631 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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
  • No spam, self-promotion, credentials, or personal data