Vmg3625 T50c FirmwareOperating system · Zyxel

CVE-2026-1459

HIGH · 7.2 CVSS v3.1 Published 2026-02-24
Fix available
A fix is available. Upgrade to after 5.50 or later.
See remediation →
78/100
Remediation priority · High
Remotely reachable 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 post-authentication command injection vulnerability in the TR-369 certificate download CGI program of the Zyxel VMG3625-T50B firmware versions through 5.50(ABPM.9.7)C0 could allow an authenticated attacker with administrator privileges to execute operating system (OS) commands on an affected device.

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 command injection vulnerability exists in the TR-369 certificate download CGI program of Zyxel VMG3625-T50B routers. An authenticated attacker with administrator privileges can inject and execute arbitrary OS commands through unsanitized input in the certificate download functionality.

MitigationApply the latest firmware patch from Zyxel when available. If no patch exists, restrict administrative access to trusted IP addresses and monitor for unauthorized administrative sessions.

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
Vmg3625 T50c FirmwareOperating system
Affected:<= 5.50\(abpm.9.7\)c0
Vmg3625 T50b FirmwareOperating system
Affected:<= 5.50\(abpm.9.7\)c0
Emg5523 T50b FirmwareOperating system
Affected:<= 5.50\(abpm.9.7\)c0
Emg3525 T50b FirmwareOperating system
Affected:<= 5.50\(abpm.9.7\)c0
Dx5401 B1 FirmwareOperating system
Affected:<= 5.17\(abyo.7.1\)c0
Vmg8623 T50b FirmwareOperating system
Affected:<= 5.50\(abpm.9.7\)c0

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
High
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:H/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 router model label or login to the admin interface and locate the model number typically displayed on the dashboard or status page
    Affected if The model is VMG3625-T50B, VMG3625-T50C, EMG5523-T50B, EMG3525-T50B, DX5401-B1, or VMG8623-T50B
  2. Check the installed firmware version
    Log into the router admin interface and navigate to the firmware version or system status page. Compare the displayed version against 5.50(abpm.9.7)c0 for T50x models or 5.17(abyo.7.1)c0 for DX5401-B1
    Affected if The firmware version is 5.50(abpm.9.7)c0 or lower for T50x models, or 5.17(abyo.7.1)c0 or lower for DX5401-B1
  3. Verify TR-369 web interface accessibility
    Attempt to access the TR-369 /cgi-bin/luci/certificate download endpoint or check if the web interface is reachable on the default HTTP/HTTPS ports (80/443)
    Affected if The router web management interface is exposed and accessible from the network being assessed
  4. Review admin access logs for suspicious activity
    Check router logs, especially authentication and administrative action logs, for unexpected administrator sessions or unusual command execution entries around the certificate download functionality
    Affected if There are log entries showing certificate download actions initiated from unexpected IP addresses or at times when no legitimate admin was logged in

The device is affected if it is one of the listed models running firmware at or below the specified version and the TR-369 administrative interface is accessible.

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
Upgrade available Upgrade to a release after 5.50
Interim mitigation

Apply the latest firmware patch from Zyxel when available. If no patch exists, restrict administrative access to trusted IP addresses and monitor for unauthorized administrative sessions.

Fix this in Vmg3625 T50c Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,300
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Scan for this in your stack

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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-2026-1459 in production — separate from our analysis above.

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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
  • No spam, self-promotion, credentials, or personal data