medium4.3
CVE-2026-39360
RustFS has an authorization bypass in multipart UploadPartCopy enables cross-bucket object exfiltration
Impact
RustFS is a distributed object storage system built in Rust. Prior to alpha.90, RustFS contains a missing authorization check in the multipart copy path (UploadPartCopy). A low-privileged user who cannot read objects from a victim bucket can still exfiltrate victim objects by copying them into an attacker-controlled multipart upload and completing the upload. This breaks tenant isolation in multi-user / multi-tenant deployments. This vulnerability is fixed in alpha.90.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rust | rustfs | <= 0.0.2 | none recorded |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Rustfs | Rustfs | Version 1.0.0 |