CVE-2026-56733: Zammad: Incorrect Authorization and Improper Privilege Management
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2 and 7.1.0, this issue concerns a lack of discursive validation within the authorization cascade. It has been determined that the system-level enforcement of access restrictions during the initialization of new identity objects exhibits a discrepancy: Under specific conditions, the granular restrictions of the access key being used are overridden by the latent authorization authority of the parent account. Consequently, this means that the intended separation of functional areas is nullified, resulting in an uncontrolled expansion of administrative discretion. Due to this potential integrity breach of the entire trust environment, an immediate evaluation of the authorization hierarchies is imperative. Impact An attacker can create new administrator accounts despite token restrictions. This grants full access to all system data (tickets, customers, configuration) and allows the attacker to take complete control of the Zammad instance. Abuse Scenario The vulnerability stems from a lack of synergy between the token-based authorization logic and the target system's functional authorization hierarchy, which allows for iterative escalation of the privileged access context. This issue is fixed in versions 7.0.2 and 7.1.0.
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 - Upgrade
Upgrade
Zammadto a version that resolves this vulnerability.Fixed in 7.1.0
Event History
Frequently Asked Questions
Which deployments are affected?
Zammad versions prior to 7.0.2 and 7.1.0 are affected. The issue concerns authorization handling when new identity objects are initialized.
What does an attacker need to exploit this issue?
The attacker needs to use an access token subject to granular restrictions under the specific conditions where the token restrictions are overridden by the parent account's authorization authority. Successful exploitation allows creation of new administrator accounts.
What is the practical impact of successful exploitation?
An attacker can obtain full administrative control of the Zammad instance. This includes access to tickets, customer data, configuration, and other system data.
What should be reviewed if remediation cannot be applied immediately?
Evaluate authorization hierarchies and access keys, particularly tokens intended to have restricted permissions. Review for newly created administrator accounts, as their creation may indicate exploitation.