What is CVE-2026-34718?

CVE-2026-34718 is a medium-severity vulnerability in Zammad, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 6.1/10. Published 2026-04-08.

How severe is CVE-2026-34718?

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

XSS in Zammad

CVE-2026-34718

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the HTML sanitizer for ticket articles was missing proper sanitization of data: ... URI schemes, resulting in storing such malicious content in the database of the Zammad instance. The Zammad GUI is rendering this content, due to applied CSP rules no harm was done by e.g., clicking such a link. This vulnerability is fixed in 7.0.1 and 6.5.4.

EPSS: 0.001 (4.6th percentile) — read the EPSS interpretation.

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.

Affected products

Zammad — versions < 6.5.4, 7.0.0, >= 7.0.0-alpha, < 7.0.1

Weakness classification (CWE)

CWE-80 — Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)

Frequently asked questions

What is CVE-2026-34718?: CVE-2026-34718 is a medium-severity vulnerability in Zammad, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 6.1/10. Published 2026-04-08.
How severe is CVE-2026-34718?: Medium severity. CVSS v3 base score is 6.1 out of 10.