Oracle Essbase: Improper access control in Essbase Web Platform
Summary
Oracle Essbase version 21.8.3.0.0 contains a flaw in the Essbase Web Platform component, classified as improper access control (CWE-284). An attacker with network access over HTTP and a low-privileged account can take over Essbase, and the impact may extend to other products (scope change). Exploitation is rated as difficult due to high attack complexity, and the CVSS base score is 8.5 (High).
Affected
- Oracle Essbase 21.8.3.0.0 (Essbase Web Platform component)
Fixed in
- Unknown. Check the row for CVE-2026-91651 in Oracle's October 2026 Critical Patch Update advisory.
Workaround
- Unknown. The CVE record provides no vendor workaround.
- Restrict access to the Essbase web interface to trusted networks or VPN as a general measure.
Exploitation
- Not listed in CISA's KEV catalogue.
- CISA SSVC assessment: exploitation none, not automatable, total technical impact.
- EPSS score: 0.003.
- No public proof of concept or confirmed exploitation found.
Our recommendation
- Check whether Essbase or a Hyperion installation is in use.
- Do not expose the Essbase web interface to the internet.
- Limit accounts to the minimum needed and review existing accounts.
- Apply the fixed version once it is confirmed in the Oracle advisory, and monitor the advisory.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Oracle Security Alert: Critical Patch Update October 2026 www.oracle.com
- Oracle CVE-to-advisory mapping www.oracle.com
- VulDB: CVE-2026-91651 vuldb.com
- OpenCVE: CVE-2026-91651 app.opencve.io
- Vulners: CNNVD-2026-60213398 vulners.com
- Essbase 21c release notes docs.oracle.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 10:17.
Original description (NVD)
Vulnerability in Oracle Essbase (component: Essbase Web Platform). The supported version that is affected is 21.8.3.0.0. Difficult to exploit 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 takeover of Oracle Essbase. CVSS 3.1 Base Score 8.5 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H).
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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