CVE-2026-40856Network attack vector

Unauthenticated credential disclosure via exposed CGI endpoint

Published Sep 16, 2026 · Updated Sep 16, 2026

Improper access control in WNC T-Mobile 5G Box IDU firmware before 1.1.0.651412 allows remote attackers to retrieve configuration secrets. The wnc_maccheck.cgi endpoint accepts unauthenticated requests and returns the administrator web password, Wi-Fi passphrase, and device details. Network access to the router's management interface is sufficient, and disclosure enables administrative login and Wi-Fi access.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Improper access control in WNC T-Mobile 5G Box IDU firmware before 1.1.0.651412 allows remote attackers to retrieve configuration secrets. The wnc_maccheck.cgi endpoint accepts unauthenticated requests and returns the administrator web password, Wi-Fi passphrase, and device details. Network access to the router's management interface is sufficient, and disclosure enables administrative login and Wi-Fi access.

The record

CVE
CVE-2026-40856
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
WNC Corporation
Product
T-Mobile 5G Box IDU
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.1.0.651412

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

WNC Corporation · T-Mobile 5G Box IDUversion=0 <1.1.0.651412

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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