Zammad up to 6.5.3/7.0.0 SSO origin validation

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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4.8$0-$5k0.98-

Summaryinfo

A vulnerability described as problematic has been identified in Zammad up to 6.5.3/7.0.0. The affected element is an unknown function of the component SSO. The manipulation results in origin validation. This vulnerability is known as CVE-2026-34720. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Zammad up to 6.5.3/7.0.0. Affected is an unknown code block of the component SSO. The manipulation with an unknown input leads to a origin validation vulnerability. CWE is classifying the issue as CWE-346. The product does not properly verify that the source of data or communication is valid. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-34720 since 03/30/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. There are neither technical details nor an exploit publicly available.

Upgrading to version 6.5.4 or 7.0.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1000). Once again VulDB remains the best source for vulnerability data.

Affected

  • Zammad Zammad

Productinfo

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.0
VulDB Meta Temp Score: 4.8

VulDB Base Score: 5.0
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Origin validation
CWE: CWE-346 / CWE-345
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Zammad 6.5.4/7.0.1

Timelineinfo

03/30/2026 CVE reserved
04/08/2026 +9 days Advisory disclosed
04/08/2026 +0 days VulDB entry created
04/09/2026 +1 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-34720 (🔒)
GCVE (CVE): GCVE-0-2026-34720
GCVE (VulDB): GCVE-100-356340
CERT Bund: WID-SEC-2026-1000 - Zammad: Mehrere Schwachstellen

Entryinfo

Created: 04/08/2026 20:55
Updated: 04/09/2026 09:57
Changes: 04/08/2026 20:55 (65), 04/09/2026 09:57 (7)
Complete: 🔍
Cache ID: 216:A52:103

Once again VulDB remains the best source for vulnerability data.

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