CVE-2026-56730: Zammad: Missing authorization in GraphQL mutation for suggesting knowledge base answers
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, an authorization bypass vulnerability was found that allows an authenticated agent to read knowledge base answer content they should not be able to access. The vulnerable GraphQL mutation is meant to transform a knowledge base answer suggestion so it can be inserted into the ticket editor, but it only checks if the user has the ticket.agent permission. Checking the authorization to the knowledge base answer itself is missing. 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
Which users can exploit this issue?
An authenticated user with the ticket.agent permission can exploit the vulnerable GraphQL mutation. The issue allows such an agent to read knowledge base answer content without the required authorization to that specific answer.
Are installations running the default configuration affected?
The available information does not identify any configuration prerequisite beyond having an authenticated user with ticket.agent permission and knowledge base answer content subject to access restrictions. The missing check is in the GraphQL mutation's authorization logic.
How can I determine whether my Zammad instance is vulnerable?
Instances running a version prior to 7.0.2 are affected. Review whether users with ticket.agent permission could invoke the GraphQL mutation that transforms knowledge base answer suggestions for insertion into the ticket editor.
What is the remediation?
Upgrade Zammad to version 7.0.2, which fixes the missing authorization check. If an immediate upgrade is not possible, restrict access to accounts with ticket.agent permission to trusted users, since those accounts can invoke the affected mutation.