What is CVE-2021-40390?

CVE-2021-40390 is a critical-severity vulnerability in Moxa Mxview, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2022-04-14.

How severe is CVE-2021-40390?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Moxa Mxview

CVE-2021-40390

An authentication bypass vulnerability exists in the Web Application functionality of Moxa MXView Series 3.2.4. A specially-crafted HTTP request can lead to unauthorized access. An attacker can send an HTTP request to trigger this vulnerability.

Published 2022-04-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.025 (83.8th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 83.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.024 · newest: 0.025 · change: +0.000

Affected products

Moxa Mxview — versions 3.2.4
Moxa Mxview Series — versions 3.2.4

Weakness classification (CWE)

CWE-798 — Use of Hard-coded Credentials

References

talosintelligence.com/vulnerability_reports/TALOS-2021-1401 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-40390?: CVE-2021-40390 is a critical-severity vulnerability in Moxa Mxview, classified under Use of Hard-coded Credentials. CVSS score: 9.8/10. Published 2022-04-14.
How severe is CVE-2021-40390?: Critical severity. CVSS v3 base score is 9.8 out of 10.