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wid-sec-w-2026-1000  ·  Published 2026-04-07  ·  View on BSI CERT-Bund ↗

Zammad: Multiple Vulnerabilities

CVSS 8.7 HIGH

Risk Summary

Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1, customers in shared organizations (means they can see each other's tickets) could see fields which are not intended for customers - including fields not intended for them at all (e.g. priority, custom ticket attributes for internal purposes). This was the case when a customer opened a ticket from another user of the same shared organization. They are not able to modify these field. This vulnerability is fixed in 7.0.1. Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the HTML sanitizer for ticket articles was missing proper sanitization of data: ... URI schemes, resulting in storing such malicious content in the database of the Zammad instance. The Zammad GUI is rendering this content, due to applied CSP rules no harm was done by e.g., clicking such a link. This vulnerability is fixed in 7.0.1 and 6.5.4. Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the webhook model was missing a proper validation for loop back addresses, or link-local addresses — only the URL scheme (HTTP/HTTPS) as well as the hostname was checked. This could end up in retrieving confidential metadata of cloud/hosting providers. The existing check is now extended and is applied when configuring webhooks as well as triggering webhook jobs. This vulnerability is fixed in 7.0.1 and 6.5.4. Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the SSO mechanism in Zammad was not verifying the header originates from a trusted SSO proxy/gateway before applying further actions on it. This vulnerability is fixed in 7.0.1 and 6.5.4. Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.1 and 6.5.4, the OAuth callback endpoints for Microsoft, Google, and Facebook external credentials do not validate a CSRF state parameter. This vulnerability is fixed in 7.0.1 and 6.5.4.

Affected Vendors

Zammad

Affected Products (4)

Zammad · Zammad <7.0.1
Zammad · Zammad 7.0.1
Zammad · Zammad <6.5.4
Zammad · Zammad 6.5.4

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