CVE-2020-26034: Zammad

Medium severity, CVSS 4.3. EPSS: 0.7% chance of exploitation in the next 30 days.

An account-enumeration issue was discovered in Zammad before 3.4.1. The Create User functionality is implemented in a way that would enable an anonymous user to guess valid user email addresses. The application responds differently depending on whether the input supplied was recognized as associated with a valid user.

Affected products

• Zammad Zammad: from 1.0.0, before 3.4.1 (fixed in 3.4.1)

Published 2020-12-28. Last modified 2026-06-17.