---
cve: "CVE-2021-4026"
severity: "MEDIUM"
cvss: 6.5
epss: "90%"
vendor: "BookStackApp"
kev: false
exploited: false
published: "2021-11-30 19:55:10"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-10T05:45:55+02:00"
---

# CVE-2021-4026

> 6.5 MEDIUM · 🧪 PoC

## Beschreibung

bookstack is vulnerable to Improper Access Control

## CVSS-Vektor

```
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
```

| 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 | Keine | good |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- d00ac2f34ecf61556b6f6ec02cb1dcafb0012b0a (Commit)
- b4fa82e3298a15443ca40bff205b7a16a1031d92 (Commit)

## Referenzen

- <https://huntr.dev/bounties/c6dfa80d-43e6-4b49-95af-cc031bb66b1d>
- <https://github.com/bookstackapp/bookstack/commit/b4fa82e3298a15443ca40bff205b7a16a1031d92>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2021-4026) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_