---
id: CVE-2026-40857
title: >-
  WNC T-Mobile 5G Box IDU router contains a cross-site request forgery (CSRF)
  vulnerability in the portal.cgi component
summary: >-
  WNC T-Mobile 5G Box IDU router contains a cross-site request forgery (CSRF)
  vulnerability in the portal.cgi component. The anti-CSRF mechanism fails to
  validate the csrf_token_value parameter, accepting any arbitrary value as
  valid. This…
severity: high
cvss: 8.4
cvssVector: 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N'
cwe:
  - CWE-352
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-2026-40857'
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: '2026-09-16T16:00:38.020709Z'
cvssSource: cna
ingestedAt: '2026-09-16T11:54:38.960Z'
epss: 0.00197
epssPercentile: 0.08354
---

## Overview

WNC T-Mobile 5G Box IDU router contains a cross-site request forgery (CSRF) vulnerability in the portal.cgi component. The anti-CSRF mechanism fails to validate the csrf_token_value parameter, accepting any arbitrary value as valid. This allows a remote attacker to perform unauthorized actions on the device by tricking an authenticated user into visiting a malicious website.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.