CVE-2026-73285 json
RustFS: OPA policy plugin omits ExistingObjectTag conditions, allowing tag-based authorization policies to treat tagged objects as untagged
published 3mo ago modified 2mo ago also EUVD-2026-57229 , GHSA-5w8r-p896-6vq2
Unreviewed: the maintainers' own advisory
Published by the maintainers on their GitHub repository rustfs/rustfs. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 40%
- public exploits
- 0
- none known
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_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.
Patch / fix
- rustfs rustfs 1.0.0-rc.1
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 2mo ago
Exploit prediction
0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-11).
Exploits and checks
- github.com https://github.com/rustfs/rustfs/security/advisories/GHSA-5w8r-p896-6vq2 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H |
Affected products
- rustfs rustfs
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
- github.com /rustfs/rustfs/commit/98d3619613722308498494d412797a52ea8ae64d
-
github.com
/rustfs/rustfs/security/advisories/GHSA-5w8r-p896-6vq2
exploit, advisory
- github.com /rustfs/rustfs/blob/380ed40b471887014fe21d069b61df9eacca074b/.agents/skills/security-advisory-lessons/referenc
- github.com /rustfs/rustfs/releases/tag/1.0.0-rc.1
Sources
- CVE List CVE-2026-73285
- NVD CVE-2026-73285
- Maintainer advisory GHSA-5w8r-p896-6vq2
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
The maintainers of rustfs/rustfs published their own advisory on GitHub. Reviewed sources take precedence over it.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.