What is CVE-2016-4842?

CVE-2016-4842 is a medium-severity vulnerability in Cybozu Mailwise, classified under Information Disclosure. CVSS score: 4.3/10. Published 2017-04-20.

How severe is CVE-2016-4842?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Information disclosure in Cybozu Mailwise

CVE-2016-4842

Cybozu Mailwise before 5.4.0 allows remote attackers to obtain information on when an email is read.

Vulnerability class: Information Disclosure

Published 2017-04-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.016 (74.6th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 74.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Cybozu Mailwise — versions 5.0.0, 5.0.1, 5.0.4

Weakness classification (CWE)

CWE-200 — Information Disclosure

References

support.cybozu.com/ja-jp/article/9606 (Vendor Advisory)
jvndb.jvn.jp/en/contents/2016/JVNDB-2016-000136.html (VDB Entry, Third Party Advisory, third-party-advisory)
jvn.jp/en/jp/JVN02576342/index.html (VDB Entry, Third Party Advisory, third-party-advisory)
www.securityfocus.com/bid/92460 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2016-4842?: CVE-2016-4842 is a medium-severity vulnerability in Cybozu Mailwise, classified under Information Disclosure. CVSS score: 4.3/10. Published 2017-04-20.
How severe is CVE-2016-4842?: Medium severity. CVSS v3 base score is 4.3 out of 10.