CVE-2026-34720: Zammad

Medium severity, CVSS 4.3. EPSS: 0.1% 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 SSO mechanism in Zammad was not verifying the header originates from a trusted SSO proxy/gateway before applying further actions on it. 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.