---
id: CVE-2026-40855
title: WNC T-Mobile 5G Box IDU router is vulnerable to a command injection
summary: >-
  WNC T-Mobile 5G Box IDU router is vulnerable to a command injection. The
  vulnerability exists in the ping functionality within the /cgi-bin/portal.cgi
  endpoint, specifically affecting the ping_ip, ping_size, and ping_times POST
  parameter…
severity: critical
cvss: 9.3
cvssVector: 'CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'
cwe:
  - CWE-78
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-2026-40855'
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: total
  timestamp: '2026-09-16T16:01:43.879737Z'
cvssSource: cna
ingestedAt: '2026-09-16T11:54:38.961Z'
epss: 0.01592
epssPercentile: 0.74654
---

## Overview

WNC T-Mobile 5G Box IDU router is vulnerable to a command injection. The vulnerability exists in the ping functionality within the /cgi-bin/portal.cgi endpoint, specifically affecting the ping_ip, ping_size, and ping_times POST parameters. The root cause is the failure to verify and sanitize user-supplied input before incorporating it into a system command. This allows an authenticated attacker to execute arbitrary commands on the shell and gain root access to the system.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.