---
id: CVE-2026-73285
title: RustFS is a distributed object storage system built in Rust
summary: >-
  RustFS is a distributed object storage system built in Rust. From
  1.0.0-alpha.64 until 1.0.0-rc.1, RustFS external OPA authorization enabled by
  RUSTFS_POLICY_PLUGIN_URL in crates/iam/src/sys.rs sets
  PreparedIamAuth.needs_existing_object_…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-863
published: '2026-08-12'
updated: '2026-09-09'
sourceUpdated: '2026-09-09T20:55:04.493'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-73285'
references:
  - url: >-
      https://github.com/rustfs/rustfs/blob/380ed40b471887014fe21d069b61df9eacca074b/.agents/skills/security-advisory-lessons/references/advisory-patterns.md?plain=1#L47
    label: security-advisories@github.com
  - url: >-
      https://github.com/rustfs/rustfs/commit/98d3619613722308498494d412797a52ea8ae64d
    label: security-advisories@github.com
  - url: 'https://github.com/rustfs/rustfs/releases/tag/1.0.0-rc.1'
    label: security-advisories@github.com
  - url: 'https://github.com/rustfs/rustfs/security/advisories/GHSA-5w8r-p896-6vq2'
    label: security-advisories@github.com
  - url: 'https://github.com/rustfs/rustfs/security/advisories/GHSA-5w8r-p896-6vq2'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00465
epssPercentile: 0.37518
ingestedAt: '2026-09-09T21:22:45.531Z'
---

## Overview

RustFS is a distributed object storage system built in Rust. From 1.0.0-alpha.64 until 1.0.0-rc.1, RustFS external OPA authorization enabled by RUSTFS_POLICY_PLUGIN_URL in crates/iam/src/sys.rs sets PreparedIamAuth.needs_existing_object_tag incorrectly for PreparedIamMode::Opa, causing maybe_merge_object_tag_conditions to omit s3:ExistingObjectTag/* values and allowing authenticated users to bypass tag-based policy restrictions. This issue is fixed in version 1.0.0-rc.1.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.