Oracle Essbase: Improper access control allows unauthenticated attacks over HTTP
Summary
A flaw in the Security component of Oracle Essbase 21.8.3.0.0 allows an unauthenticated remote attacker with network access via HTTP to compromise the server. Successful attacks can lead to unauthorized read access to critical data, and in some cases unauthorized update, insert or delete access to data. Because the scope changes, the impact may extend beyond Essbase to other products.
Affected
- Oracle Essbase 21.8.3.0.0
- No other affected versions listed in the CVE record.
Fixed in
Unknown. Oracle's October 2026 Critical Patch Update (released 20 October 2026) includes Essbase, but the fixed version for this CVE has not been confirmed.
Workaround
- None provided in the CVE record.
- General hardening until patched: restrict network access to the Essbase HTTP service to trusted administrative networks.
Exploitation
- Exploited in the wild: not known.
- CISA SSVC: exploitation none, automatable yes, technical impact partial.
- Not listed in CISA KEV.
- No public proof of concept found (search was limited).
Our recommendation
- Inventory all Essbase instances, including vendor- or partner-hosted ones, and confirm their versions.
- Apply the October 2026 Critical Patch Update or the Oracle-recommended fix as soon as the fixed version is confirmed.
- Until patched, restrict access to the Essbase HTTP service from the internet and less-trusted networks.
- Monitor for unusual HTTP requests to Essbase and recheck exploitation status regularly.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Oracle Critical Patch Update Advisory October 2026 www.oracle.com
- Oracle Security Blog: October 2026 Critical Patch Update released blogs.oracle.com
- VulDB CVE-2026-91644 vuldb.com
- OpenCVE CVE-2026-91644 app.opencve.io
- Vulners CVE-2026-91644 vulners.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 31 Oct 2026, 01:03.
Original description (NVD)
Vulnerability in Oracle Essbase (component: Security). The supported version that is affected is 21.8.3.0.0. Easily exploitable vulnerability allows unauthenticated 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. CVSS 3.1 Base Score 9.3 (Confidentiality and Integrity impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N).
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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