W20e FirmwareOperating system · Tenda

CVE-2026-24115

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Public exploit 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
An issue was discovered in Tenda W20E V4.0br_V15.11.0.6. Failure to validate the sizes of `gstup` and `gstdwn` before concatenating them into `gstruleQos` may lead to buffer overflow.

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

Buffer overflow vulnerability in Tenda W20E V4.0br_V15.11.0.6 where the `gstup` and `gstdwn` HTTP parameters are concatenated into the `gstruleQos` buffer without validating their sizes, allowing potential remote code execution.

MitigationUpdate to vendor-provided patched firmware when available; otherwise, disable or restrict access to the affected QoS configuration functionality.

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
W20e FirmwareOperating system
Affected:= 15.11.0.6

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 checks

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

  1. Identify the device model
    Check the device label or web interface for the model name 'W20E' to confirm this is the affected product
    Affected if The device is a Tenda W20E router
  2. Check the firmware version
    Log into the router web interface (typically 192.168.0.1) and navigate to System Status or Firmware Upgrade page to find the firmware version, or use the command 'cat /proc/version' via telnet/SSH if available
    Affected if The firmware version is exactly 15.11.0.6
  3. Verify the web management interface is accessible
    Attempt to access the router's web interface on the default IP (192.168.0.1) over HTTP/HTTPS
    Affected if The web interface is reachable on the network
  4. Confirm QoS feature is enabled
    Navigate to the QoS settings page in the router web interface (usually under Bandwidth Control or QoS) and check if the feature is configured or enabled
    Affected if The QoS feature is accessible and the gstruleQos parameter would be processed
  5. Check for unauthenticated access to the affected endpoint
    Send a POST request to the form handler that processes gstup/gstdwn parameters (typically /goform/ or /cgi-bin/ endpoint) without authentication to see if the parameters are accepted
    Affected if The vulnerable parameter processing endpoint accepts the gstup or gstdwn parameters without requiring authentication

You are affected if you have a Tenda W20E device running firmware version 15.11.0.6 with the QoS feature accessible through the web interface.

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

Update to vendor-provided patched firmware when available; otherwise, disable or restrict access to the affected QoS configuration functionality.

Fix this in W20e Firmware Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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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-2026-24115 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
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