Memory Buffer Bounds ErrorWeakness · CWE-119

CVE-2026-7218

HIGH · 7.2 CVSS v3.1 Published 2026-04-28
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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 vulnerability was detected in Totolink N300RT 3.4.0-B20250430. The impacted element is the function is_cmd_string_valid of the file /boafrm/formWsc of the component libapmib.so. Performing a manipulation of the argument localPin results in buffer overflow. The attack is possible to be carried out remotely. The exploit is now public and may be used.

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

Buffer overflow in the is_cmd_string_valid function within libapmib.so (/boafrm/formWsc) of Totolink N300RT firmware 3.4.0-B20250430 allows remote attackers to overflow the localPin parameter, potentially leading to code execution. The vulnerability affects the WSC (Wi-Fi Simple Config) web interface component.

MitigationApply vendor firmware update when available; if no update exists, restrict access to the router's web management interface to trusted networks only to reduce remote attack surface.

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
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
    Access the router's web administrative interface or check the device label/metadata to confirm the model is Totolink N300RT
    Affected if The device is not a Totolink N300RT router - this vulnerability only affects this specific model
  2. Check the firmware version
    Log into the router web interface and navigate to System Status or Firmware Upgrade page to view the current firmware version, or use the router's admin CLI if available
    Affected if The firmware version matches v3.4.0-B20250430 exactly, or falls within the range containing this version (v3.4.0-B20250430 and related builds)
  3. Verify the vulnerable web component exists
    Check if the file /boafrm/formWsc is accessible on the router's web server by attempting to access http://<router-ip>/boafrm/formWsc or by examining the firmware image for the presence of this CGI handler
    Affected if The /boafrm/formWsc endpoint is present and responds to requests
  4. Confirm WPS/WSC functionality is enabled
    Log into the router admin panel and check Wireless Settings > WPS (Wi-Fi Protected Setup) or WSC (Wi-Fi Simple Config) settings to see if this feature is enabled
    Affected if WPS/WSC functionality is enabled on the device - the buffer overflow occurs through the localPin parameter to this feature
  5. Check for the vulnerable library
    If firmware extraction is possible, locate libapmib.so within the firmware filesystem and verify the is_cmd_string_valid function exists within it
    Affected if The libapmib.so library contains the is_cmd_string_valid function and it performs insufficient bounds checking on the localPin parameter

The device is affected if it is a Totolink N300RT running firmware v3.4.0-B20250430 or a related version, with the /boafrm/formWsc endpoint present and WPS/WSC functionality enabled.

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 update when available; if no update exists, restrict access to the router's web management interface to trusted networks only to reduce remote attack surface.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2026-7218 in production — separate from our analysis above.

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What this is

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What belongs here
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