CVE-2026-27607
RustFS's Missing Post Policy Validation leads to Arbitrary Object Write
CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th
RustFS is a distributed object storage system built in Rust. In versions 1.0.0-alpha.56 through 1.0.0-alpha.82, RustFS does not validate policy conditions in presigned POST uploads (PostObject), allowing attackers to bypass content-length-range, starts-with, and Content-Type constraints. This enables unauthorized file uploads exceeding size limits, uploads to arbitrary object keys, and content-type spoofing, potentially leading to storage exhaustion, unauthorized data access, and security bypasses. Version 1.0.0-alpha.83 fixes the issue.
| CWE | CWE-20 CWE-863 |
| Vendor | rustfs |
| Product | rustfs |
| Published | Feb 25, 2026 |
| Last Updated | Feb 25, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
Affected Versions
rustfs / rustfs
>= 1.0.0-alpha.56, < 1.0.0-alpha.83