CVE-2026-91651 in Essbase
Summary
by MITRE • 10/22/2026
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).
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Analysis
by VulDB Data Team • 10/22/2026
The identified vulnerability resides within the Essbase Web Platform component of Oracle Essbase version 21.8.3.0.0, representing a critical security flaw that allows for unauthorized access and potential system compromise. This specific weakness is characterized by its difficulty to exploit, which implies that while it requires careful planning or specific conditions to trigger successfully, it does not rely on user interaction such as clicking malicious links. The attack vector is network-based via HTTP, meaning an attacker can initiate the exploitation process remotely without needing physical access to the target system. This remote accessibility significantly increases the risk profile for organizations relying on this software for business intelligence and analytics operations.
The core technical flaw enables a low-privileged attacker with valid network connectivity to escalate their privileges or manipulate the application state in ways that lead to full takeover of Oracle Essbase. The term take over indicates that an adversary can gain control equivalent to a system administrator, allowing them to execute arbitrary code, modify configurations, and access sensitive data stores. This level of compromise is particularly dangerous because it bypasses standard authentication mechanisms designed for lower-level users, effectively neutralizing the security boundaries established by database administrators.
A critical aspect of this vulnerability is its potential scope change, where attacks targeting Oracle Essbase can significantly impact additional products within the broader ecosystem. In enterprise environments, components are often interconnected through shared libraries, databases, or identity management systems. A compromise in one component like Essbase Web Platform can serve as a pivot point for lateral movement across other integrated services. This cascading effect means that securing this single vulnerability is not just about protecting Essbase but also safeguarding the integrity of the entire application suite and associated data infrastructure.
The operational impact of exploiting this flaw is severe, reflected in a CVSS 3.1 Base Score of 8.5 which denotes a High severity rating. The vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H) details the specific dimensions of risk. Network Attack Vector indicates remote exploitability, while High Complexity suggests that successful exploitation requires non-trivial conditions or precise timing. Low Privileges Required means even basic user accounts can be leveraged to launch the attack, and No User Interaction confirms it is fully automated once triggered. The Scope Change from C to C highlights the lateral movement risk mentioned earlier. Most critically, the impacts on Confidentiality, Integrity, and Availability are all rated as High, meaning attackers can exfiltrate sensitive data, alter critical business metrics or configurations, and disrupt service availability simultaneously.
From a classification perspective, this vulnerability aligns with CWE categories related to privilege escalation and insecure direct object references if it involves accessing resources without proper authorization checks. It also maps to MITRE ATT&CK techniques involving initial access via web applications and potentially credential dumping or persistence mechanisms depending on the exact exploitation method used by attackers. Understanding these mappings helps in configuring intrusion detection systems to look for specific patterns associated with this type of privilege escalation attack.
Mitigation strategies must prioritize immediate patching if an update is available from Oracle that addresses this specific flaw in version 21.8.3.0.0. In the absence of a direct patch, organizations should implement strict network segmentation to limit HTTP access to the Essbase Web Platform only from trusted IP ranges or internal subnets. Additionally, enforcing multi-factor authentication for all administrative accounts and applying principle of least privilege can reduce the impact if an attacker gains initial low-level access. Monitoring logs for unusual activity patterns indicative of exploitation attempts is essential for early detection. Regular vulnerability assessments and penetration testing should be conducted to identify similar weaknesses in related components before they are exploited by malicious actors seeking to compromise the broader enterprise environment.