Di 8003 FirmwareOperating system · Dlink

CVE-2025-50659

HIGH · 7.5 CVSS v3.1 Published 2026-04-08
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
A buffer overflow vulnerability exists in D-Link DI-8003 16.07.26A1 due to improper handling of the custom_error parameter in the /user.asp endpoint.

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 buffer overflow vulnerability exists in D-Link DI-8003 router firmware version 16.07.26A1 in the custom_error parameter of the /user.asp endpoint. The improper handling of user-supplied input allows an attacker to overflow a buffer, potentially leading to remote code execution or denial of service conditions.

MitigationSince the DI-8003 is a legacy device with limited support, apply network access controls to restrict who can reach the /user.asp endpoint, consider network segmentation, and evaluate replacing with a currently supported device if no firmware patch is available.

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
Di 8003 FirmwareOperating system
Affected:= 16.07.26a1

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 device model
    Access the router administration interface or check the device label to confirm it is a D-Link DI-8003 router model.
    Affected if The device is not a D-Link DI-8003 model - if so, this CVE does not apply.
  2. Check the firmware version
    Log into the router web interface (typically at 192.168.0.1) and navigate to System Status or Firmware Upgrade page to view the installed firmware version. Alternatively, check the firmware file name or version displayed on the device status page.
    Affected if The installed firmware version is exactly 16.07.26a1 - other versions are not affected by this specific CVE.
  3. Verify the /user.asp web interface is accessible
    Attempt to access http://[router-ip]/user.asp in a web browser. If the page loads or returns any response (including an error), the endpoint exists.
    Affected if The /user.asp endpoint responds (the vulnerability requires this interface to be reachable).
  4. Check if remote management is enabled
    In the router web interface, look under Settings, Administration, or Remote Management. Verify whether remote (WAN) access to the web interface is permitted.
    Affected if Remote management is enabled and the /user.asp interface is exposed to the WAN, the device is vulnerable to remote exploitation.

The device is affected only if it is a D-Link DI-8003 router running firmware version 16.07.26a1 AND the /user.asp web interface is accessible (especially from WAN).

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

Since the DI-8003 is a legacy device with limited support, apply network access controls to restrict who can reach the /user.asp endpoint, consider network segmentation, and evaluate replacing with a currently supported device if no firmware patch is available.

Fix this in Di 8003 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,690
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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-2025-50659 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
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