CVE-2026-40937

Severity CVSS v4.0:

Pending analysis

Type:

Unavailable / Other

Publication date:

22/04/2026

Last modified:

22/04/2026

Description

RustFS is a distributed object storage system built in Rust. Prior to 1.0.0-alpha.94, all four notification target admin API endpoints in `rustfs/src/admin/handlers/event.rs` use a `check_permissions` helper that validates authentication only (access key + session token), without performing any admin-action authorization via `validate_admin_request`. Every other admin handler in the codebase correctly calls `validate_admin_request` with a specific `AdminAction`. This is the only admin handler file that skips authorization. A non-admin user can overwrite a shared admin-defined notification target by name, causing subsequent bucket events to be delivered to an attacker-controlled endpoint. This enables cross-user event interception and audit evasion. 1.0.0-alpha.94 contains a patch.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L CVSS v3.1 Severity and Metrics:

Base Score: 8.30 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): Low

Base Score 3.x

8.30

Severity 3.x

HIGH

CVE-2026-40937

Description

Impact

References to Advisories, Solutions, and Tools