Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessReach Essbase HTTP endpoint
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DeliverySend crafted unauthenticated request
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ExploitAbuse flaw in Security component
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ExecutionGain unauthorized data access across scope
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ImpactRead critical data and perform limited writes
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Access control enforcement
MITRE ATT&CK
1 technique across 1 tactic: Defense Evasion The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Exploitation Conditions | Exploitation requires network reachability to the Oracle Essbase HTTP service on a host running the affected build 21.8.3.0.0; per the CVSS vector (AV:N/AC:L/PR:N/UI:N) no authentication, no special privileges, and no user interaction are needed against a reachable instance. The flaw resides in the Essbase Security component and carries a scope change (S:C), so impact may extend to additional connected Oracle products. The primary limiting factor is exposure of the Essbase HTTP interface - instances isolated behind network segmentation, not internet-facing, or restricted by upstream access controls are substantially less exposed; the vendor identifies only version 21.8.3.0.0 as affected, so deployments on other versions may not be vulnerable. |
| Impact | Signals are strongly aligned toward high priority, with one caveat: the CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N, base 9.3) describes the worst-case exposure profile - remote, network-reachable over HTTP, low attack complexity, no privileges and no user interaction, with a scope change that lets the compromise reach beyond Essbase itself. The dominant impact is confidentiality (C:H) with limited integrity (I:L) and no availability impact (A:N), so this is primarily a data-exposure/unauthorized-access flaw rather than a service-disruption one. No EPSS score, no CISA KEV listing, and no public POC were provided, so there is no evidence of active exploitation or weaponization - the 9.3 reflects potential severity, not observed activity. The 'Authentication Bypass' tag is directionally consistent with PR:N (unauthenticated) but is not independently corroborated by the Oracle description, which only states 'unauthenticated attacker'; treat the bypass framing as unconfirmed. Net: a genuinely high-priority patch target for any organization running the affected Essbase build because of the trivial unauthenticated network reach and scope change, but the absence of KEV/EPSS/POC signals means exploitation is currently theoretical and likely not yet widespread - prioritize patching without assuming imminent mass exploitation. |
| Exploit ScenarioDerived | A remote, unauthenticated attacker who can reach the Oracle Essbase HTTP interface sends a crafted request to the vulnerable Security component, requiring no credentials, no user interaction, and only low attack complexity. Because of the scope change, successful exploitation yields read access to critical Essbase data and limited unauthorized modification, and may extend impact into additional connected products. No public exploit code was identified at time of analysis. |
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Alert meAnalysisAIv1 – Oct 20, 2026
Unauthenticated remote attackers can exploit an authentication bypass in the Security component of Oracle Essbase 21.8.3.0.0 over HTTP, gaining unauthorized access to critical data and limited ability to modify it, with potential impact extending to connected Oracle products due to a scope change. The vulnerability carries a CVSS 9.3 base score; no public exploit identified at time of analysis, and no CISA KEV entry confirms active exploitation. Risk is highest for instances with internet-facing or otherwise network-reachable Essbase HTTP services, while segmented or access-restricted deployments are less exposed.
RemediationAI
Apply the Oracle Critical Patch Update (October 2026) for Oracle Essbase; consult https://www.oracle.com/security-alerts/cpuoct2026.html for the exact patched version and instructions. Until patching is complete, restrict network access to the Essbase HTTP interface using firewalls, security groups, or upstream access controls, and avoid exposing the service directly to the internet. Because the vulnerability has a scope change, isolate Essbase from other Oracle products and sensitive network segments to limit lateral impact. Monitor HTTP logs for unauthenticated requests or anomalous data access. Trade-offs: network restrictions may disrupt legitimate remote users and integrations; segmentation may require architectural changes and could affect cross-product workflows; disabling or limiting HTTP endpoints may reduce functionality.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Oracle Essbase is an OLAP server used for business analytics, and its Security component handles authentication and authorization. CVE-2026-91644 is an authentication bypass (per Oracle's tagging) that allows a remote, unauthenticated attacker (CVSS PR:N) with network access to the Essbase HTTP interface to bypass security controls and access or modify data. The CVSS vector AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N indicates low attack complexity, no user interaction, and a scope change (S:C) that can let the compromise affect other products beyond Essbase. The root cause class is not assigned a CWE in the available data, but the flaw is specifically in the Security component. Only version 21.8.3.0.0 is identified as affected by the vendor; exploitation requires reachability to the Essbase HTTP service on that build.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
Oracle describes unauthenticated HTTP access with no user interaction (AV:N/AC:L/PR:N/UI:N), a scope change to other products (S:C), high confidentiality and low integrity impact, no availability impact.
Primary rating from Vendor (oracle).
CVSS VectorVendor: oracle
DescriptionCVE.org
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).
Executive ViewAI
Oracle Essbase 21.8.3.0.0 suffers from a critical authentication bypass (CVSS 9.3) that could let remote attackers access and modify critical data, with potential scope expansion to connected Oracle products. Leadership should care because no vendor patch is available, leaving internet-facing or network-reachable Essbase HTTP services exposed to data confidentiality and integrity risks, even though no public exploit has been identified yet.
No vendor-released patch identified at time of analysis. Interim mitigations include restricting network access to Essbase HTTP services to trusted IP ranges, implementing additional authentication (e.g., reverse proxy with MFA), segmenting Essbase from connected Oracle products, and monitoring logs for anomalous access patterns.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
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EUVD-2026-106831
GHSA-9xf3-7hgg-hxj8
NVD
CVE.org
EPSS
Exploit-DB