CVE-2026-55838

RustFS: Missing admin authorization on /rustfs/admin/v3/metrics allows any authenticated user to read server metrics

MEDIUM
4.3
CVSS Score
Published: June 26, 2026 at 07:57 PM UTC
Updated: June 27, 2026 at 11:42 AM UTC
1 product affected across 1 vendorRustfs

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 1.0.0-beta.7

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-862

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