CVE-2026-39360: Rustfs

Medium severity, CVSS 4.3. EPSS: 0.3% chance of exploitation in the next 30 days.

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 products

• Rustfs Rustfs: version 1.0.0 only

Published 2026-04-07. Last modified 2026-07-24.