---
cve: "CVE-2026-91656"
severity: "CRITICAL"
cvss: 9.1
epss: "0.2%"
vendor: "Oracle Corporation"
kev: false
exploited: false
published: "2026-10-20 22:21:05"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-11-08T03:50:56+01:00"
---

# CVE-2026-91656

> 9.1 CRITICAL

## Beschreibung

Vulnerability in Oracle Essbase (component: Federated Partitions).   The supported version that is affected is 21.8.3.0.0. Easily exploitable vulnerability allows low privileged attacker with network access via HTTP to compromise Oracle Essbase.  While the vulnerability is in Oracle Essbase, attacks may significantly impact additional products (scope change).  Successful attacks of this vulnerability can result in  unauthorized access to critical data or complete access to all Oracle Essbase accessible data as well as  unauthorized update, insert or delete access to some of Oracle Essbase accessible data and unauthorized ability to cause a partial denial of service (partial DOS) of Oracle Essbase. CVSS 3.1 Base Score 9.1 (Confidentiality, Integrity and Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L).

## CNA-Record (Kanon, cvelistV5)

- CNA: **oracle**
- State: PUBLISHED
- Stand: 2026-10-27 21:24:14
- CNA-CVSS: **9.1** (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **partial**

## CVSS-Vektor

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

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

## Schwachstellen-Klasse

- **CWE-284** — Improper Access Control
  The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

## Angriffsmuster (CAPEC)

- [CAPEC-19 — Embedding Scripts within Scripts](https://capec.mitre.org/data/definitions/19.html) _(Severity: High)_
- [CAPEC-441 — Malicious Logic Insertion](https://capec.mitre.org/data/definitions/441.html) _(Severity: High)_
- [CAPEC-478 — Modification of Windows Service Configuration](https://capec.mitre.org/data/definitions/478.html) _(Severity: High)_
- [CAPEC-479 — Malicious Root Certificate](https://capec.mitre.org/data/definitions/479.html) _(Severity: Low)_
- [CAPEC-502 — Intent Spoof](https://capec.mitre.org/data/definitions/502.html)
- [CAPEC-503 — WebView Exposure](https://capec.mitre.org/data/definitions/503.html)
- [CAPEC-536 — Data Injected During Configuration](https://capec.mitre.org/data/definitions/536.html) _(Severity: High)_
- [CAPEC-546 — Incomplete Data Deletion in a Multi-Tenant Environment](https://capec.mitre.org/data/definitions/546.html) _(Severity: Medium)_

## ATT&CK-Techniken

- [T1027.009 — Obfuscated Files or Information: Embedded Payloads](https://attack.mitre.org/techniques/T1027/009/)
- [T1546.004 — Event Triggered Execution:.bash_profile and .bashrc](https://attack.mitre.org/techniques/T1546/004/)
- [T1546.016 — Event Triggered Execution: Installer Packages](https://attack.mitre.org/techniques/T1546/016/)
- [T1574.011 — Hijack Execution Flow:Service Registry Permissions Weakness](https://attack.mitre.org/techniques/T1574/011/)
- [T1543.003 — Create or Modify System Process:Windows Service](https://attack.mitre.org/techniques/T1543/003/)
- [T1553.004 — Subvert Trust Controls:Install Root Certificate](https://attack.mitre.org/techniques/T1553/004/)

## Referenzen

- <https://www.oracle.com/security-alerts/cpuoct2026.html>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-91656/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_