Vulnerability · Published Sep 25, 2026 · Assigned by GitHub_M
CVE-2026-56725Zammad: Denial of Service via OTRS Import Controller
High 8.7
In plain English
A high-severity missing authentication in zammad from zammad. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities).
Official description
Zammad is a web based open source helpdesk/customer support system. Prior to 7.0.2, summary An unauthenticated request to POST /api/v1/import/otrs/import_check blocks a Zammad request worker for roughly two minutes. The import_check and import_status actions are missing the setup_done_response guard that other actions in the same controller carry, so they execute on fully set-up production instances. The action enters a retry loop against a blank OTRS endpoint, sleeping for 30 s + 45 s between attempts. Impact An unauthenticated remote attacker denies service to a production Zammad instance. Each request costs almost nothing and forces ~115 seconds of server-side blocking. A few requests per second saturate the Puma worker pool. The condition persists as long as the traffic continues. No account, valid import configuration, or target knowledge beyond the hostname is needed. CSRF token is trivially obtained from any prior GET response. This issue is fixed in version 7.0.2.
Affected products (as reported)
Weakness: CWE-306, CWE-400 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/zammad/zammad/security/advisories/GHSA-45cx-9mrq-mmcj x_refsource_CONFIRM
- https://github.com/zammad/zammad/commit/a04a95b69496306af4c1fbd369a54981122e67c0 x_refsource_MISC
- https://github.com/zammad/zammad/releases/tag/7.0.2 x_refsource_MISC