dbcve.org
Improper Input ValidationWeakness · CWE-20

CVE-2025-11676

HIGH · 7.1 CVSS v4.0 Published 2025-11-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
76/100
Remediation priority · High
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
Improper input validation vulnerability in TP-Link System Inc. TL-WR940N V6 (UPnP modules), which allows unauthenticated adjacent attackers to perform DoS attack. This issue affects TL-WR940N V6 <= Build 220801.

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

Improper input validation vulnerability in the UPnP modules of TP-Link TL-WR940N V6 routers (Build 220801 and below) allows unauthenticated attackers on the adjacent network to send specially crafted UPnP requests that cause a denial of service condition due to insufficient validation of input data.

MitigationApply the vendor-supplied firmware patch when available; as a workaround, disable UPnP functionality on the router to reduce the attack surface until the patch can be applied.

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
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 web interface or check the device label to confirm the model is TP-Link TL-WR940N V6
    Affected if The device is not a TP-Link TL-WR940N V6, then it is not affected by this specific CVE
  2. Check the firmware version
    Log into the router web interface and navigate to the Status or Firmware Upgrade page to find the current firmware build number
    Affected if The firmware build number is 220801 or lower, indicating the device is running a vulnerable version
  3. Verify if UPnP is enabled
    Access the router web interface, locate the UPnP settings (usually under Advanced or NAT settings), and check whether the UPnP function is turned on
    Affected if UPnP is enabled on the device, allowing the vulnerability to be exploited; if UPnP is disabled, the attack surface is reduced though the underlying vulnerable code may still exist

The device is affected if it is a TP-Link TL-WR940N V6 running firmware Build 220801 or below with UPnP functionality enabled, allowing adjacent network attackers to trigger denial of service via crafted UPnP requests.

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 the vendor-supplied firmware patch when available; as a workaround, disable UPnP functionality on the router to reduce the attack surface until the patch can be applied.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-11676 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2025-11676 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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