CVE-2026-84464

Received Received - Intake

Information Disclosure in Zammad Helpdesk System

Publication date: 2026-09-25

Last updated on: 2026-09-25

Assigner: GitHub, Inc.

Description

Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, zammad's External Data Source feature, used to look up records from an external system, did not properly verify whether a user was allowed to see a specific ticket, user, group, or organization before including its details in a request to that external system. An authenticated user, including one with only basic customer access, could exploit this by referencing another record's ID, and thereby view details of tickets, customer accounts, teams, or organizations that did not belong to them. This issue is fixed in version 7.1.2.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-09-25

Last Modified

2026-09-25

Generated

2026-09-26

AI Q&A

2026-09-26

EPSS Evaluated

N/A

NVD

CVE-2026-84464

EUVD

EUVD-2026-87263

Affected Vendors & Products

Vendor	Product	Version / Range
zammad	zammad	7.1.2

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-200	The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
CWE-863	The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
CWE-639	The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.

Attack-Flow Graph

Executive Summary

Zammad is a helpdesk system. Prior to version 7.1.2, its External Data Source feature did not verify if users were allowed to view specific tickets, users, groups, or organizations before sharing their details with external systems. This allowed authenticated users, even with basic access, to view unauthorized records by referencing their IDs.

Detection Guidance

This vulnerability can be detected by checking if your Zammad instance is running a version prior to 7.1.2. Use the command: zammad version to check the installed version. If the version is less than 7.1.2, the system is vulnerable.

Impact Analysis

An attacker with basic access could access sensitive information like tickets, customer accounts, teams, or organizations they shouldn't see. This could lead to data breaches, privacy violations, or unauthorized modifications if combined with other vulnerabilities.

Compliance Impact

This vulnerability could violate GDPR by exposing personal data without consent and HIPAA by leaking protected health information. Organizations using affected versions may face compliance failures, legal penalties, and reputational damage.

Mitigation Strategies

Upgrade Zammad to version 7.1.2 or later to address the vulnerability. Review and restrict access controls for authenticated users, especially those with basic customer access, to prevent unauthorized record lookups.

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