CVE-2026-56723: Zammad: Missing authorization on ticket attachment download
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, a customer who can view a ticket cannot see internal ticket articles through the article listing API. However, the same customer can directly request an attachment belonging to an internal article via the attachment download endpoint, bypassing article-level authorization. This results in an inconsistency: The article listing hides internal articles from customers. The attachment download only checks the parent ticket, not the article, so the same customer can download the attachment directly. This issue is fixed in version 7.0.2.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Zammadto a version that resolves this vulnerability.Fixed in 7.0.2
Event History
Frequently Asked Questions
Who can exploit this issue?
A customer who is authorized to view the parent ticket can exploit it. The customer does not need permission to view the internal article that owns the attachment.
What information can be exposed?
Attachments associated with internal ticket articles may be downloaded by a customer who can access the parent ticket. Internal articles themselves remain hidden through the article listing API.
Are default deployments affected?
The provided information does not identify a configuration prerequisite. Any affected Zammad version where customers can view tickets containing attachments on internal articles should be considered exposed.
What should be done to remediate the issue?
Upgrade Zammad to version 7.0.2, which fixes the authorization inconsistency in attachment downloads.