What is CVE-2018-0558?

CVE-2018-0558 is a medium-severity vulnerability in Cybozu Mailwise, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-06-26.

How severe is CVE-2018-0558?

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

XSS in Cybozu Mailwise

CVE-2018-0558

Reflected cross-site scripting vulnerability in Cybozu Mailwise 5.0.0 to 5.4.1 allows remote attackers to inject arbitrary web script or HTML in 'System settings' via unspecified vectors.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2018-06-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (55.2th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Cybozu Mailwise
Cybozu, Inc. Cybozu Mailwise — versions 5.0.0 to 5.4.1

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

jvn.jp/en/jp/JVN52319657/index.html (Third Party Advisory, third-party-advisory)
support.cybozu.com/ja-jp/article/10193 (Third Party Advisory)

Frequently asked questions

What is CVE-2018-0558?: CVE-2018-0558 is a medium-severity vulnerability in Cybozu Mailwise, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-06-26.
How severe is CVE-2018-0558?: Medium severity. CVSS v3 base score is 6.1 out of 10.