CVE-2026-34718: Zammad

Medium severity, CVSS 6.1. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Zammad Zammad: before 6.5.4 (fixed in 6.5.4); version 7.0.0 only

Published 2026-04-08. Last modified 2026-07-24.