CVE-2026-56725

Zammad: Denial of Service via OTRS Import Controller

State
Published
Severity
8.7 High
Published
Sep 25, 2026
Updated
Sep 29, 2026
Reserved
Jun 22, 2026

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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.

Scores

CVSSScoreVectorSource
4.08.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NGitHub_M

Weaknesses

  • CWE-306 Missing Authentication for Critical Function
  • CWE-400 Uncontrolled Resource Consumption

Affected Products

ProductVersions
zammadzammad
  • < 7.0.2Affected

References

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