CVE-2026-91646 in Essbase
Summary
by MITRE • 10/21/2026
Vulnerability in Oracle Essbase (component: Security). The supported version that is affected is 21.8.3.0.0. Difficult to exploit vulnerability allows unauthenticated attacker with network access via T3, IIOP to compromise Oracle Essbase. Successful attacks of this vulnerability can result in unauthorized update, insert or delete access to some of Oracle Essbase accessible data as well as unauthorized read access to a subset 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 5.6 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L).
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Analysis
by VulDB Data Team • 10/21/2026
The identified vulnerability resides within the security component of Oracle Essbase version 21.8.3.0.0, representing a significant risk to organizations relying on this enterprise analytics platform for business intelligence and data modeling operations. The flaw is characterized by its difficulty to exploit, which implies that an attacker must possess specialized knowledge or employ complex techniques to successfully trigger the underlying code defect. Despite this high barrier to entry, the vulnerability allows unauthenticated attackers who have network access via T3 or IIOP protocols to compromise the integrity of the system. These specific communication channels are commonly used for remote method invocation and distributed object interactions within Java-based enterprise applications, making them critical attack vectors if not properly secured. The presence of this flaw indicates a failure in input validation or authentication enforcement mechanisms at the protocol handling layer, allowing malicious actors to bypass standard security controls without needing valid credentials.
The operational impact of successfully exploiting this vulnerability is multifaceted, affecting confidentiality, integrity, and availability as reflected by its CVSS 3.1 base score of 5.6. An attacker can achieve unauthorized read access to a subset of data accessible within Oracle Essbase, leading to potential leakage of sensitive business intelligence metrics or proprietary analytical models. Furthermore, the vulnerability permits unauthorized updates, inserts, or deletes against certain datasets, which compromises data integrity and could lead to corrupted reporting outcomes or manipulation of key performance indicators. In addition to these data-centric impacts, the attacker can cause a partial denial of service by exhausting system resources through malformed requests sent over T3 or IIOP interfaces. This degradation in availability disrupts normal business operations that depend on real-time analytics and decision support systems, creating operational inefficiencies and potential financial losses due to downtime or delayed insights.
From a technical classification perspective, this vulnerability aligns with CWE-287 Improper Authentication, as it allows unauthenticated access to protected resources, and potentially CWE-94 Improper Control of Generation of Code (Code Injection) if the exploit involves injecting malicious logic through the IIOP interface. In terms of adversary behavior mapping under MITRE ATT&CK, this scenario corresponds to T1078 Valid Accounts or more accurately in this unauthenticated context, techniques related to Initial Access such as Exploit Public-Facing Application (T1190) and potentially Persistence mechanisms if the attacker modifies data to maintain access. The use of IIOP suggests a potential alignment with Remote Code Execution vectors often seen in Java EE environments where deserialization flaws or protocol parsing errors are leveraged, although the specific impact here is limited to data manipulation and partial DoS rather than full system compromise.
Mitigation strategies must prioritize immediate network-level restrictions given that the vulnerability affects protocols accessible over the network. Organizations should restrict access to T3 and IIOP ports by implementing strict firewall rules or Access Control Lists (ACLs) that limit connectivity to only trusted internal subnets, thereby reducing the attack surface exposed to external threats. It is critical to apply the latest security patches provided by Oracle for version 21.8.3.0.0 as soon as they become available, ensuring that the underlying code defects in the security component are addressed. Additionally, deploying Web Application Firewalls (WAFs) or Intrusion Prevention Systems (IPS) with signatures capable of detecting anomalous IIOP traffic patterns can provide an additional layer of defense against exploitation attempts. Regular audits of network configurations and continuous monitoring for unusual activity on these specific ports will further enhance the security posture surrounding Oracle Essbase deployments.