SYSTEM privilege escalation via writable preload configuration
Published Sep 15, 2026 · Updated Sep 15, 2026
Incorrect permissions in Duplicati for Windows before 2.4.0.0 allow local users to gain NT AUTHORITY\SYSTEM via a crafted preload.json file. The configuration loader trusts C:\ProgramData\Duplicati\preload.json without ensuring that only administrators can modify it, then applies attacker-controlled settings in the privileged service. Exploitation requires a low-privileged local account and a Duplicati Windows service using the insecure preload location; successful exploitation grants SYSTEM privileges.
Summary
What happened
Incorrect permissions in Duplicati for Windows before 2.4.0.0 allow local users to gain NT AUTHORITY\SYSTEM via a crafted preload.json file. The configuration loader trusts C:\ProgramData\Duplicati\preload.json without ensuring that only administrators can modify it, then applies attacker-controlled settings in the privileged service. Exploitation requires a low-privileged local account and a Duplicati Windows service using the insecure preload location; successful exploitation grants SYSTEM privileges.
The record
- CVE
- CVE-2026-76159
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- Duplicati Inc.
- Product
- Duplicati
- Classifications
- CWE-732, T1548
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 15, 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=0 <v2.4.0.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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