Stack-based Buffer OverflowWeakness · CWE-121

CVE-2026-36777

MEDIUM · 6.5 CVSS v3.1 Published 2026-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
No privileges 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
Shenzhen Tenda Technology Co., Ltd Tenda W3 Wireless Router v1.0.0.3(2204) was discovered to contain a stack overflow in the param_1 parameter of the formSetCfm function. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted HTTP request.

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

A stack buffer overflow vulnerability exists in the formSetCfm function of Tenda W3 Wireless Router firmware v1.0.0.3(2204). The vulnerability is caused by insufficient bounds checking on the param_1 parameter, allowing an attacker to send a crafted HTTP request that overwrites stack memory, leading to denial of service.

MitigationApply input validation and length checks on the param_1 parameter in the formSetCfm function; if available, update to a patched firmware version; otherwise, restrict administrative interface access to trusted networks 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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 device model
    Access the router web interface or check device label/marketing materials to confirm it is a Tenda W3 Wireless Router
    Affected if Device is not a Tenda W3 model
  2. Check firmware version
    Log into the router web interface and navigate to System Settings or Status page to view the firmware version. Alternatively, check via CLI if telnet/ssh is enabled or inspect firmware binary if accessible.
    Affected if Firmware version is 1.0.0.3(2204)
  3. Verify web management interface is accessible
    Attempt to access the router's HTTP/HTTPS web interface on the default IP (commonly 192.168.0.1 or 192.168.1.1). Determine if the interface responds to login requests.
    Affected if Web management interface is reachable from network
  4. Check remote administration exposure
    Review router settings for 'Remote Management', 'Remote Access', or 'Web Management' settings to determine if remote (WAN) access is enabled.
    Affected if Remote administration is enabled, exposing the web interface to WAN
  5. Identify vulnerable formSetCfm endpoint
    Inspect HTTP requests to the router's formSetCfm function by reviewing router's web server logs or attempting a benign request to the form handler endpoint (commonly /goform/formSetCfm or similar).
    Affected if The formSetCfm handler is present and accessible

The device is affected if it is a Tenda W3 router running firmware version 1.0.0.3(2204) with the web management interface accessible to an attacker.

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 input validation and length checks on the param_1 parameter in the formSetCfm function; if available, update to a patched firmware version; otherwise, restrict administrative interface access to trusted networks to reduce attack surface.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
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Scan for this in your stack

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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-2026-36777 in production — separate from our analysis above.

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What this is

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What belongs here
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