What is CVE-2026-4309?

CVE-2026-4309 is a medium-severity vulnerability in Nec Aterm W1200ex-Ms, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-03-27.

How severe is CVE-2026-4309?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Auth bypass in Nec Aterm W1200ex-Ms

CVE-2026-4309

Missing Authorization vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to get a specific device information and change the settings via network.

Vulnerability class: Broken Access Control

EPSS: 0.001 (3.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Nec Aterm_w1200ex-ms
Nec Aterm_w1200ex-ms_firmware
Nec Aterm_wf1200cr
Nec Aterm_wf1200cr_firmware
Nec Aterm_wg1200cr
Nec Aterm_wg1200cr_firmware
Nec Aterm_wg1200hp2
Nec Aterm_wg1200hp2_firmware
Nec Aterm_wg1200hp3
Nec Aterm_wg1200hp3_firmware

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

psirt-info@cyber.jp.nec.com (Vendor Advisory)

Frequently asked questions

What is CVE-2026-4309?: CVE-2026-4309 is a medium-severity vulnerability in Nec Aterm W1200ex-Ms, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-03-27.
How severe is CVE-2026-4309?: Medium severity. CVSS v3 base score is 6.5 out of 10.