CVE-2026-27607: Rustfs

Critical severity, CVSS 9.1. EPSS: 0.4% chance of exploitation in the next 30 days.

RustFS is a distributed object storage system built in Rust. In versions 1.0.0-alpha.56 through 1.0.0-alpha.82, RustFS does not validate policy conditions in presigned POST uploads (PostObject), allowing attackers to bypass content-length-range, starts-with, and Content-Type constraints. This enables unauthorized file uploads exceeding size limits, uploads to arbitrary object keys, and content-type spoofing, potentially leading to storage exhaustion, unauthorized data access, and security bypasses. Version 1.0.0-alpha.83 fixes the issue.

Affected products

• Rustfs Rustfs: version 1.0.0 only

Published 2026-02-25. Last modified 2026-06-17.