What is CVE-2026-4621?

CVE-2026-4621 is a medium-severity vulnerability in Nec Aterm W1200ex-Ms, classified under Hidden Functionality. CVSS score: 5.6/10. Published 2026-03-27.

How severe is CVE-2026-4621?

Medium severity. CVSS v3 base score is 5.6 out of 10.

Vulnerability in Nec Aterm W1200ex-Ms

CVE-2026-4621

Hidden Functionality vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to enable telnet via network.

Published 2026-03-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.003 (14.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

CWE-912 — Hidden Functionality

References

jpn.nec.com/security-info/secinfo/nv26-001_en.html (Vendor Advisory)

Frequently asked questions

What is CVE-2026-4621?: CVE-2026-4621 is a medium-severity vulnerability in Nec Aterm W1200ex-Ms, classified under Hidden Functionality. CVSS score: 5.6/10. Published 2026-03-27.
How severe is CVE-2026-4621?: Medium severity. CVSS v3 base score is 5.6 out of 10.