Authenticated data exfiltration via unchecked copy source
Published May 28, 2026 · Updated May 28, 2026
Improper authorization in RustFS before 1.0.0-beta.9 allows remote authenticated users to copy objects across buckets via UploadPartCopy. The upload_part_copy handler checks GetObject on the source and PutObject on the destination independently, but never enforces destination policy constraints on the copy source. Read access to the source and write access to the destination are required, enabling sensitive objects to be staged in an attacker-controlled bucket.
Summary
What happened
Improper authorization in RustFS before 1.0.0-beta.9 allows remote authenticated users to copy objects across buckets via UploadPartCopy. The upload_part_copy handler checks GetObject on the source and PutObject on the destination independently, but never enforces destination policy constraints on the copy source. Read access to the source and write access to the destination are required, enabling sensitive objects to be staged in an attacker-controlled bucket.
The record
- CVE
- CVE-2026-45042
- Published
- May 28, 2026
- Updated
- May 28, 2026
- Vendor
- RustFS
- Product
- RustFS
- Classifications
- CWE-863, T1530
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 28, 2026CVE publishedPublication date reported by the CVE source.
- May 28, 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=< 1.0.0-beta.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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.
Public exploit references
- GHSA-wfxj-ph3v-7mjf embedded proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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