Vulnerability · Published Aug 12, 2026 · Assigned by GitHub_M

CVE-2026-73285RustFS: OPA policy plugin omits ExistingObjectTag conditions, allowing tag-based authorization policies to treat tagged objects as untagged

High 7.5

In plain English

A high-severity incorrect authorization in rustfs from rustfs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.5%top 59.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
rustfs	rustfs	>= 1.0.0-alpha.64, < 1.0.0-rc.1

Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

References

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