---
id: CVE-2026-40856
title: WNC T-Mobile 5G Box IDU router is vulnerable to improper access control
summary: >-
  WNC T-Mobile 5G Box IDU router is vulnerable to improper access control. The
  vulnerability exists in the wnc_maccheck.cgi endpoint, which is accessible
  without authentication. It allows a remote attacker to retrieve sensitive
  configurati…
severity: high
cvss: 7.1
cvssVector: 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-306
vendor: WNC
product: T-Mobile 5G Box IDU
affected:
  - t-mobile_5g_box_idu < 1.1.0.651412
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T19:14:25.980'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-40856'
references:
  - url: 'https://cert.pl/posts/2026/09/CVE-2026-40854'
    label: cvd@cert.pl
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-16T16:01:03.097066Z'
cvssSource: cna
ingestedAt: '2026-09-16T11:54:38.960Z'
epss: 0.00373
epssPercentile: 0.28501
---

## Overview

WNC T-Mobile 5G Box IDU router is vulnerable to improper access control. The vulnerability exists in the wnc_maccheck.cgi endpoint, which is accessible without authentication. It allows a remote attacker to retrieve sensitive configuration data, including the administrator web password, WiFi passphrase, and technical device information.This issue has been fixed in firmware version 1.1.0.651412

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.