CVE-2020-26029: Zammad

Medium severity, CVSS 6.5. EPSS: 0.8% chance of exploitation in the next 30 days.

An issue was discovered in Zammad before 3.4.1. There are wrong authorization checks for impersonation requests via X-On-Behalf-Of. The authorization checks are performed for the actual user and not the one given in the X-On-Behalf-Of header.

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.