---
id: "CVE-2026-91639"
kind: "vulnerability"
aliases: ["CVE-2026-91639"]
title: "Oracle Essbase: low-privileged HTTP attacker gains access to critical data"
severity: "high"
cvss: 7.7
epss: 0.00371
exploited: false
status: "open"
category: "vendor"
products: [{"name": "oracle essbase", "fixed": [], "affected": "= 21.8.3.0.0", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["http", "oracle-essbase", "self-hosted", "vendor"]
not_affected_if: ["no-http-exposure", "other-version"]
published_at: "2026-10-20T22:21:03+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T03:10:36+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91639", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91639", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# Oracle Essbase: low-privileged HTTP attacker gains access to critical data

Oracle Essbase 21.8.3.0.0 has a flaw in its Security component that lets a low-privileged user reach data over HTTP. Per the CVSS vector, a successful attack can expose critical data and may affect other products (scope change), with no integrity or availability impact listed.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:oracle essbase affected = 21.8.3.0.0 fixed ?

## How to check

- Confirm the Essbase version with the installed build; the sources list 21.8.3.0.0 as affected
- Check the Oracle Critical Patch Update advisory for the patch level that covers this CVE (unknown from the sources)

## Fix

- Apply the Oracle patch for Essbase referenced in the Oracle advisory for CVE-2026-91639 (exact fixed version unknown from the sources)

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91639
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91639

## From the sources

Vulnerability 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 this vulnerability can result in  unauthorized access to critical data or complete access to all Oracle Essbase accessible data. CVSS 3.1 Base Score 7.7 (Confidentiality impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N).

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