What’s Vulnerable › Vulnerabilities

CVE-2020-26029

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-12-28 · updated 2026-06-17
• Weakness: CWE-863

Description

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: from 1.0.0 before 3.4.1 — fixed in 3.4.1

How to fix

Upgrade to a fixed version: zammad 3.4.1. Check the vendor advisory for mitigations.

References

• https://zammad.com/news/security-advisory-zaa-2020-20
• https://zammad.com/news/security-advisory-zaa-2020-20

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