---
cve: "CVE-2026-40937"
severity: "HIGH"
cvss: 8.3
epss: "0.3%"
vendor: "rustfs"
kev: false
exploited: false
published: "2026-04-22 20:15:57"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T19:54:54+02:00"
---

# CVE-2026-40937

> 8.3 HIGH · 🧪 PoC

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Gering | warn |

## Patch verfügbar (OSV)

- c0d3f53f7ad1b4267e6760d48845928b06ea1ea4 (Commit)

## Referenzen

- <https://github.com/rustfs/rustfs/security/advisories/GHSA-pfcq-4gjr-6gjm>
- <https://github.com/rustfs/rustfs/releases/tag/1.0.0-alpha.94>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-40937) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_