CVE-2020-26030

9.8 criticalEPSS 1.4%

Critical (9.8) in zammad zammad. EPSS 1.4% chance of exploitation in the next 30 days.

An issue was discovered in Zammad before 3.4.1. There is an authentication bypass in the SSO endpoint via a crafted header, when SSO is not configured. An attacker can create a valid and authenticated session that can be used to perform any actions in the name of other users.

Severity

CVSS 3.1

9.8 critical

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 1.4% chance of exploitation in the next 30 days; higher than 71% of CVEs (scores of 2026-10-31)
CWE: CWE-287
Published: 2020-12-28
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

zammad:zammad

References

https://zammad.com/news/security-advisory-zaa-2020-18
https://zammad.com/news/security-advisory-zaa-2020-18

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