What is CVE-2020-5631?

CVE-2020-5631 is a medium-severity vulnerability in Cmonos, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2020-10-06.

How severe is CVE-2020-5631?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Cmonos

CVE-2020-5631

Stored cross-site scripting vulnerability in CMONOS.JP ver2.0.20191009 and earlier allows remote attackers to inject arbitrary script via unspecified vectors.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2020-10-06 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.010 (62.5th percentile), scored 2026-10-05.

Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 62.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Cmonos — versions 2.0.20200916
Cmonos Co. Ltd. Cmonos.jp — versions ver2.0.20191009 and earlier

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

cmonos.jp/download/history.html (Vendor Advisory)
cmonos.jp/download/index.shtml (Vendor Advisory)
jvn.jp/en/vu/JVNVU93741515/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2020-5631?: CVE-2020-5631 is a medium-severity vulnerability in Cmonos, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2020-10-06.
How severe is CVE-2020-5631?: Medium severity. CVSS v3 base score is 6.1 out of 10.