Missing AuthenticationWeakness · CWE-306

CVE-2026-25084

CRITICAL · 9.8 CVSS v3.1 Published 2026-02-11
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
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
Authentication for ZLAN5143D can be bypassed by directly accessing internal URLs.

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

This is an authentication bypass vulnerability in ZLAN5143D (a serial-to-Ethernet converter device). Attackers can circumvent authentication mechanisms by directly accessing internal URLs, likely through path traversal or improper access control on the device's web interface. The critical CVSS score suggests the vulnerability is exploitable remotely without any prior authentication.

MitigationRestrict network exposure of affected devices behind firewalls or VPNs, apply network segmentation, and check vendor firmware updates for patches addressing this authentication bypass.

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
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
    Access the device's web interface or check the device label/marketing materials to confirm the model is ZLAN5143D. Some devices display model info on the login page or in the footer.
    Affected if The device model is ZLAN5143D and matches the affected product line.
  2. Determine the firmware version
    Log into the device web interface and navigate to the System Settings or Status page to find the firmware version. If no login is possible, check any administrative interface or documentation for version information.
    Affected if The installed firmware version is unknown or unpatched for this authentication bypass vulnerability.
  3. Verify web interface authentication
    Access the device login page from a browser. Observe whether unauthenticated access to internal URLs is possible by attempting to access common paths like /admin, /status, /config, or similar endpoints without logging in.
    Affected if Internal pages or administrative functions are accessible without authentication credentials.
  4. Test for path traversal or URL bypass
    Attempt to access known internal API endpoints or pages directly by modifying the URL path, for example adding ../ or accessing absolute paths like /internal/status.htm without authentication.
    Affected if Direct URL access returns sensitive information or administrative pages without requiring login.
  5. Check network exposure
    Determine if the device web interface is accessible from the internet or untrusted networks. Scan external IP ranges or review firewall rules to identify if port 80/443 or custom web ports are exposed.
    Affected if The device web interface is reachable from untrusted networks without VPN or firewall protection.

If the device is a ZLAN5143D with an exposed web interface where internal URLs are accessible without authentication, the environment is likely affected by this CVE.

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

Restrict network exposure of affected devices behind firewalls or VPNs, apply network segmentation, and check vendor firmware updates for patches addressing this authentication bypass.

Have this fixed 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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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-25084 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2026-25084 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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