EUVD Vulnerability Catalog

EUVD-2026-80669

Severity: HIGH Base Score: 8.7 CVSS Version: 4.0

Vulnerability Description

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

CVSS Vector Analysis

Below is the complete, human-readable breakdown of the CVSS metric string: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

▪ Attack Vector (AV): Adjacent Network

▪ Attack Complexity (AC): Low

▪ Attack Requirements (AT): None

▪ Privileges Required (PR): None

▪ User Interaction (UI): None

▪ Vulnerability Confidentiality Impact (VC): High

▪ Vulnerability Integrity Impact (VI): High

▪ Vulnerability Availability Impact (VA): High

▪ Subsequent Confidentiality Impact (SC): None

▪ Subsequent Integrity Impact (SI): None

▪ Subsequent Availability Impact (SA): None

Affected Vendors & Systems

Vendor WNC

References & Advisory Links

https://cert.pl/posts/2026/09/CVE-2026-40854

Metadata Profile

Database Authority

European Union Agency for Cybersecurity (ENISA) EUVD

Assigner

CERT-PL

EPSS Probability

Known Aliases

CVE-2026-40854 GHSA-7wq2-g42r-wr2h

Published On

2026-09-16

Last Updated

2026-09-16