CVE-2026-56725 zammad CVE debrief

Who should care

Defenders of Zammad instances should assess exposure and apply the patch to prevent potential denial of service attacks. Defenders should prioritize verifying exposure and applying the patch to prevent potential denial of service attacks. This vulnerability affects Zammad instances prior to version 7.0.2. Defenders should review compensating controls for exposed systems while remediation is scheduled and verified.

Why it matters

An unauthenticated remote attacker can cause a denial of service to a production Zammad instance by making requests to the /api/v1/import/otrs/import_check endpoint. Defenders should prioritize verifying exposure and applying the patch to prevent potential denial of service attacks.

• Denial of service to production Zammad instances
• Server-side blocking of Zammad request workers

Technical summary

The import_check and import_status actions in Zammad are missing the setup_done_response guard, allowing an unauthenticated request to block a Zammad request worker for roughly two minutes. The issue is fixed in version 7.0.2. This vulnerability affects Zammad instances prior to version 7.0.2. The vulnerability has a high impact on Zammad instances, and defenders should prioritize verifying exposure and applying the patch. The import_check and import_status actions are missing the setup_done_response guard, which allows an unauthenticated request to block a Zammad request worker.

Defensive priority

Defenders should prioritize verifying exposure and applying the patch to prevent potential denial of service attacks.

Recommended defensive actions

• Verify if the Zammad instance is vulnerable to this issue
• Apply the patch to prevent potential denial of service attacks
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source references provide information on the vulnerability and the fix. However, there is limited information on potential exploitation or impact. The vulnerability affects Zammad instances prior to version 7.0.2. Defenders should verify if the Zammad instance is vulnerable to this issue and apply the patch to prevent potential denial of service attacks. The CVE record and source references provide information on the vulnerability and the fix.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.