Auth bypass in Oracle Corporation Essbase

CVE-2026-91665

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 TCP to compromise Oracle Essbase. Successful attacks of this vulnerability can result in takeover of Oracle Essbase. CVSS 3.1 Base Score 9.8 (Confidentiality, Integrity and Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-91665?
CVE-2026-91665 is a critical-severity vulnerability in Oracle Corporation Essbase, classified under Improper Authentication. CVSS score: 9.8/10. Published 2026-10-20.
How severe is CVE-2026-91665?
Critical severity. CVSS v3 base score is 9.8 out of 10.