CVE-2026-40854

Unrated0% EPSS

WNC T-Mobile 5G Box IDU router contains an authentication bypass vulnerability in the portal.cgi component. The session verification mechanism improperly validates the sessionid cookie by checking for the existence of a corresponding file in /tmp/login_user. An attacker can bypass authentication by using directory entries such as "." or ".." in the cookie, allowing unauthorized access to the administration panel.This issue has been fixed in firmware version 1.1.0.651412

Published 2026-09-16 · last modified 2026-09-16

Full record at NVD ↗

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Ncerio by BeyondNets · data from NVD, CISA KEV, EPSS.