CVE-2026-91656 in Essbase
Summary
by MITRE • 10/22/2026
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).
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Analysis
by VulDB Data Team • 10/22/2026
The identified vulnerability resides within the Federated Partitions component of Oracle Essbase version 21.8.3.0.0, representing a critical security flaw that undermines the integrity and confidentiality of enterprise data analytics environments. This specific module is responsible for managing distributed data partitions across multiple sources, and its compromise allows an attacker to bypass standard access controls due to insufficient validation or authorization checks within the partition handling logic. The vulnerability is classified as easily exploitable by low-privileged attackers who possess network access via HTTP, indicating that no complex exploitation techniques or user interaction are required to trigger the malicious code path. This ease of exploitation significantly lowers the barrier for entry, allowing adversaries with minimal credentials to initiate attacks against the system remotely over standard web protocols.
The operational impact of this vulnerability is severe and multifaceted, affecting not only Oracle Essbase but potentially extending to other integrated products within the broader ecosystem due to scope changes in attack vectors. Successful exploitation grants unauthorized access to critical data, effectively compromising confidentiality at a high level as indicated by the CVSS 3.1 base score of 9.1. Beyond mere data theft, the flaw permits unauthorized updates, inserts, and deletes against accessible data, thereby violating integrity principles. This capability allows attackers to alter analytical results or corrupt datasets that drive business decisions. Furthermore, the vulnerability enables partial denial of service conditions, disrupting availability for legitimate users by exhausting system resources or causing application instability through malformed requests targeting the federated partition mechanisms.
From a technical classification perspective, this incident aligns with Common Weakness Enumeration categories such as CWE-269 Improper Privilege Management and CWE-798 Use of Hard-coded Credentials if authentication bypass is involved, though the primary concern remains unauthorized data manipulation and access. In terms of adversary behavior mapping to MITRE ATT&CK, this vulnerability facilitates techniques related to Initial Access via valid accounts or service credentials, followed by Data Exfiltration over Application Layer Protocol for confidentiality breaches, and Impact through Data Manipulation or Service Exhaustion. The high availability impact suggests potential alignment with Denial of Service tactics where resource consumption is weaponized against the Essbase infrastructure.
Mitigation strategies must prioritize immediate patching to version 21.8.3.0.0 or later if available, ensuring that all security updates provided by Oracle are applied promptly. Network segmentation should be enforced to restrict HTTP access to the Federated Partitions component strictly from trusted internal networks rather than exposing it directly to untrusted zones. Implementing Web Application Firewalls with rulesets designed to detect anomalous partition queries can provide an additional layer of defense against exploitation attempts. Additionally, organizations should review and harden authentication mechanisms for Essbase services, ensuring that even low-privileged accounts are subject to strict least-privilege principles and multi-factor authentication where applicable. Continuous monitoring of access logs for unusual patterns in partition requests will aid in early detection of potential compromise activities targeting this specific component.