CVE-2026-91655 Oracle CVE debrief

Who should care

Oracle Essbase administrators, security teams responsible for vulnerability management, IT personnel overseeing critical data protection, and operators managing affected systems. These stakeholders should be aware of the critical severity of this vulnerability and the potential for significant impact, including data breaches and service disruption. They should assess exposure, apply patches or mitigations, and monitor for potential unauthorized access or

Why it matters

This critical vulnerability in Oracle Essbase requires immediate attention from administrators and security teams due to its potential for significant impact, including data breaches and service disruption. The vulnerability's critical severity and potential for exploitation highlight the need for prompt assessment and remediation.

• Potential unauthorized access to critical data or complete access to all Oracle Essbase accessible data.
• Potential unauthorized update, insert or delete access to some of Oracle Essbase accessible data.
• Potential partial denial of service (partial DOS) of Oracle Essbase.

Technical summary

The vulnerability in Oracle Essbase 21.8.3.0.0 is easily exploitable by a low-privileged attacker with network access via HTTP. This could potentially lead to unauthorized access to critical data, update, insert or delete access to some data, and partial denial of service. The CVSS 3.1 Base Score is 9.1, indicating critical severity. The 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

Defensive priority

High priority for immediate assessment and remediation due to critical severity and potential for significant impact.

Recommended defensive actions

• Assess exposure of Oracle Essbase 21.8.3.0.0 in your environment.
• Verify if any additional products are impacted by this vulnerability.
• Apply patches or mitigations as recommended by Oracle.
• Monitor for potential unauthorized access or denial of service attempts.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE and NVD records provide details on the vulnerability, its impacts, and affected versions. Oracle's advisory is referenced but not detailed in the corpus. The vulnerability is in Oracle Essbase (component: Security). 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

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.