Classic Buffer OverflowWeakness · CWE-120

CVE-2026-36818

HIGH · 7.5 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 →
84/100
Remediation priority · High
Remotely reachable 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 W20E v15.11.0.6 was discovered to contain a buffer overflow in the wewifiWhiteUserInfo parameter of the formAddWewifiWhiteUser 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 · high confidence

A buffer overflow vulnerability exists in the Tenda W20E router firmware v15.11.0.6 within the formAddWewifiWhiteUser function's wewifiWhiteUserInfo parameter. Attackers can send a specially crafted HTTP request with oversized input to trigger the overflow, causing the device to crash and resulting in Denial of Service.

MitigationApply vendor-supplied firmware updates when available; until then, restrict administrative web interface access to trusted networks or disable the wewifi white user feature if not needed.

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/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 the router firmware version
    Access the router admin web interface (typically at 192.168.0.1) and navigate to System Settings > Firmware Version, or log in via telnet/SSH and run 'cat /proc/version' or 'cat /etc/os-release' to retrieve the firmware build number
    Affected if The firmware version is v15.11.0.6 exactly, or falls within an unpatched version range that contains this build
  2. Confirm the specific affected function exists
    Check if the /goform/formAddWewifiWhiteUser endpoint is present on the router's web server by reviewing the firmware's web server binary or by attempting a request to that endpoint (if accessible)
    Affected if The formAddWewifiWhiteUser function is present in the firmware binary
  3. Verify wewifi (guest WiFi) feature is enabled
    Log into the router admin panel and check if Guest WiFi (wewifi) is enabled under Wireless Settings > Guest WiFi, or inspect the router's configuration file for wewifi settings
    Affected if The Guest WiFi (wewifi) feature is enabled and the white user list management function is accessible
  4. Determine web interface exposure
    Check if the router's HTTP/HTTPS management interface is reachable from the WAN (internet) side by reviewing port forwarding rules, remote management settings, or scanning the public IP for port 80/443
    Affected if The router's web management interface is exposed to untrusted network segments or the WAN interface

You are affected if your Tenda W20E runs firmware v15.11.0.6 (or an unpatched version) AND the guest WiFi feature is enabled AND the management interface is accessible to untrusted attackers.

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-supplied firmware updates when available; until then, restrict administrative web interface access to trusted networks or disable the wewifi white user feature if not needed.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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Scan for this in your stack

Free · runs locally
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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-2026-36818 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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