{"id":"CVE-2026-40854","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-40854","generatedAt":"2026-10-28T05:59:53.976Z","title":"WNC T-Mobile 5G Box IDU router contains an authentication bypass vulnerability in the portal.cgi component.","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","published":"2026-09-16T12:17:04.000Z","lastModified":"2026-09-28T23:10:00.000Z","status":"Awaiting Analysis","sourceIdentifier":"cvd@cert.pl","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-290"],"affected":[],"epss":{"score":0.00319,"percentile":0.24702,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.32%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://cert.pl/posts/2026/09/CVE-2026-40854","source":"cvd@cert.pl"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-40854","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}