Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-4493

HIGH · 8.8 CVSS v3.1 Published 2026-03-20
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
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 vulnerability was determined in Tenda A18 Pro 02.03.02.28. The impacted element is the function sub_423B50 of the file /goform/setMacFilterCfg of the component MAC Filtering Configuration Endpoint. Executing a manipulation of the argument deviceList can lead to stack-based buffer overflow. The attack may be performed from remote. The exploit has been publicly disclosed and may be utilized.

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 stack-based buffer overflow vulnerability exists in the Tenda A18 Pro firmware version 02.03.02.28 within the MAC filtering configuration endpoint (/goform/setMacFilterCfg). The vulnerable function sub_423B50 fails to properly bounds-check the deviceList parameter before copying it to a stack-allocated buffer, allowing remote attackers to overflow the buffer and potentially execute arbitrary code on the affected device.

MitigationApply vendor firmware updates when available; if no patch exists, restrict network access to the device's web management interface and consider disabling MAC filtering functionality until a fix is released.

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

CVSS:3.1/AV:N/AC:L/PR:L/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 web interface or check the device label/metadata to confirm the model is Tenda A18 Pro
    Affected if Device is not a Tenda A18 Pro unit
  2. Check the installed firmware version
    Log into the device web interface and navigate to the system settings or firmware upgrade page to view the current firmware version, or use commands like 'cat /proc/version' or 'ver' via telnet/SSH if available
    Affected if Firmware version is 02.03.02.28 or earlier unpatched versions
  3. Verify MAC filtering functionality is accessible
    Log into the device web interface and check if there is a MAC filtering configuration section under Wireless or Security settings
    Affected if MAC filtering feature is present and configurable in the web interface
  4. Confirm network exposure of the management interface
    Check if the device web interface (typically on ports 80 or 443) is accessible from untrusted networks by scanning the device IP from an external location or reviewing firewall rules
    Affected if The web management interface is exposed to untrusted networks (WAN or public networks)
  5. Check if MAC filtering is enabled
    In the device web interface, verify whether MAC filtering has been configured or enabled in the wireless security or access control settings
    Affected if MAC filtering is enabled or configured with a device list

The device is affected if it is a Tenda A18 Pro running firmware version 02.03.02.28 with the MAC filtering feature accessible and enabled, especially if the management interface is exposed to untrusted networks.

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 vendor firmware updates when available; if no patch exists, restrict network access to the device's web management interface and consider disabling MAC filtering functionality until a fix is released.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2026-4493 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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