What is CVE-2018-1000154?

CVE-2018-1000154 is a medium-severity vulnerability in Zammad, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-04-05.

How severe is CVE-2018-1000154?

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

XSS in Zammad

CVE-2018-1000154

Zammad GmbH Zammad version 2.3.0 and earlier contains a Improper Neutralization of Script-Related HTML Tags in a Web Page (CWE-80) vulnerability in the subject of emails which are not html quoted in certain cases. This can result in the embedding and execution of java script code on users browser. This attack appear to be exploitable via the victim openning a ticket. This vulnerability appears to have been fixed in 2.3.1, 2.2.2 and 2.1.3.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2018-04-05 · 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: 0.015 (74.0th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 74.0% 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: 0.015 · change: -0.000

Affected products

Zammad

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/zammad/zammad/issues/1869 (Third Party Advisory)
zammad.com/news/release-2-4 (Vendor Advisory)
zammad.com/news/security-advisory-zaa-2018-01 (Vendor Advisory)

Frequently asked questions

What is CVE-2018-1000154?: CVE-2018-1000154 is a medium-severity vulnerability in Zammad, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2018-04-05.
How severe is CVE-2018-1000154?: Medium severity. CVSS v3 base score is 6.1 out of 10.