All vulnerabilities
CVE-2026-56725GHSA-45cx-9mrq-mmcj

Zammad: Denial of Service via OTRS Import Controller

zammad zammadApplications & CMS
CVSS
8.7High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.41%Chance of exploitation activity in the next 30 days, higher than 34% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published25 Sep 2026Updated 29 Sep 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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.

Text from CVE List

Affected versions 1

  • zammadaffected: < 7.0.2CVE List

References 3