Denial of service via unguarded import retries
Published Sep 25, 2026 · Updated Sep 25, 2026
Denial of service in Zammad before 7.0.2 allows remote attackers to block request workers through the OTRS import API. The import_check and import_status actions lack the setup_done_response guard, so a blank OTRS endpoint triggers retries with long sleeps. No account or valid import configuration is required; sustained requests occupy the Puma worker pool and interrupt service while traffic continues.
Summary
What happened
Denial of service in Zammad before 7.0.2 allows remote attackers to block request workers through the OTRS import API. The import_check and import_status actions lack the setup_done_response guard, so a blank OTRS endpoint triggers retries with long sleeps. No account or valid import configuration is required; sustained requests occupy the Puma worker pool and interrupt service while traffic continues.
The record
- CVE
- CVE-2026-56725
- Published
- Sep 25, 2026
- Updated
- Sep 25, 2026
- Vendor
- Zammad GmbH
- Product
- Zammad
- Classifications
- CWE-400, CWE-306, T1499.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 25, 2026CVE publishedPublication date reported by the CVE source.
- Sep 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 7.0.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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