CVE-2026-56728: Zammad: Cross-User Taskbar Item Access Control Vulnerability
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, a broken access control vulnerability exists in Zammad's GraphQL API. An authenticated user can access taskbar item data belonging to another user by crafting a request with the target user's taskbar identifier. The taskbar feature stores transient state for active user sessions, including auto-saved ticket drafts. Under certain conditions, the authorization check for taskbar item access is not enforced, allowing a user to read another user's taskbar item data. This vulnerability is fixed in 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?
An authenticated Zammad user can exploit it by crafting a GraphQL request that uses another user's taskbar identifier. The issue is therefore relevant to deployments where untrusted or lower-privileged users can authenticate.
What information could be exposed?
An attacker may read another user's taskbar item data. Because taskbar items can contain transient active-session state, exposed data can include auto-saved ticket drafts.
Which versions need remediation?
Zammad versions prior to 7.0.2 are affected. The vulnerability is fixed in version 7.0.2.