---
id: "CVE-2026-91654"
kind: "vulnerability"
aliases: ["CVE-2026-91654"]
title: "Oracle Essbase: low-privilege HTTP attacker can read, change and disrupt data"
severity: "medium"
cvss: 6.3
epss: 0.00175
exploited: false
status: "open"
category: "vendor"
products: [{"name": "oracle essbase", "fixed": [], "affected": "= 21.8.3.0.0", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["enterprise-bi", "oracle-essbase", "vendor"]
not_affected_if: ["fixed-version", "no-http-access"]
published_at: "2026-10-20T22:21:05+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T04:01:29+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91654", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91654", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# Oracle Essbase: low-privilege HTTP attacker can read, change and disrupt data

Oracle Essbase 21.8.3.0.0 has a Security component flaw that lets a low-privilege user reach it over HTTP. A successful attack can read and modify a subset of accessible data and partly disrupt the service.

_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 installed Essbase version is `21.8.3.0.0` (the sources list this as the affected version)
- Check Oracle's April 2026 Critical Patch Update advisory for the Essbase entry (unknown whether the sources name a specific patch)

## Fix

- Apply the Oracle patch for Essbase that addresses CVE-2026-91654 (the fixed version is unknown from the sources)
- Restrict HTTP access to Essbase to trusted networks until patched

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91654
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91654

## 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.  Successful attacks of this vulnerability can result in  unauthorized update, insert or delete access to some of Oracle Essbase accessible data as well as  unauthorized read access to a subset 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 6.3 (Confidentiality, Integrity and Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L).

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_