CVE-2026-40856: Wnc T-Mobile 5g Box Idu

High severity, CVSS 7.1. EPSS: 0.4% chance of exploitation in the next 30 days.

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

Affected products

• Wnc T-Mobile 5g Box Idu: before 1.1.0.651412 (fixed in 1.1.0.651412)

Published 2026-09-16. Last modified 2026-09-28.