CVE-2026-40857: Wnc T-Mobile 5g Box Idu

High severity, CVSS 8.4. EPSS: 0.2% chance of exploitation in the next 30 days.

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

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.