CVE-2026-55838: 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. In 1.0.0-beta.7 and earlier, the real-time metrics endpoint at /rustfs/admin/v3/metrics is accessible to any valid IAM user regardless of their assigned policy. Every other admin handler in the codebase calls validate_admin_request to enforce admin-action IAM checks; the MetricsHandler skips this call entirely. A restricted IAM user whose policy grants only access to their own bucket can read server-wide operational metrics including disk I/O statistics, network throughput, scanner cycle timing, and cluster RPC state.

Affected products

• Rustfs Rustfs: up to and including 1.0.0-beta.7

Published 2026-06-26. Last modified 2026-06-27.