CVE-2026-73285 PUBLISHED

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.

• https://github.com/rustfs/rustfs/security/advisories/GHSA-5w8r-p896-6vq2
• https://github.com/rustfs/rustfs/commit/98d3619613722308498494d412797a52ea8ae64d
• https://github.com/rustfs/rustfs/blob/380ed40b471887014fe21d069b61df9eacca074b/.agents/skills/security-advisory-lessons/references/advisory-patterns.md?plain=1#L47
• https://github.com/rustfs/rustfs/releases/tag/1.0.0-rc.1

• CWE-863: Incorrect Authorization CWE