---
id: "CVE-2026-91657"
kind: "vulnerability"
aliases: ["CVE-2026-91657"]
title: "Oracle Essbase: low-privilege HTTP user can read a subset of data"
severity: "medium"
cvss: 4.3
epss: 0.00184
exploited: false
status: "open"
category: "vendor"
products: [{"name": "oracle essbase", "fixed": [], "affected": "= 21.8.3.0.0", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["oracle-essbase", "self-hosted", "vendor"]
not_affected_if: []
published_at: "2026-10-20T22:21:06+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T04:37:47+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91657", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91657", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# Oracle Essbase: low-privilege HTTP user can read a subset of data

A flaw in the Security component of Oracle Essbase 21.8.3.0.0 lets an attacker with a low-privilege account reach the product over HTTP. A successful attack gives unauthorized read access to a subset of data Essbase holds.

_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` (unknown how to read it from the sources; check the Essbase admin console or installed package)

## Fix

- Apply the Oracle Critical Patch Update that addresses CVE-2026-91657 for Essbase (unknown fixed version in the sources)

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91657
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91657

## 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 read access to a subset of Oracle Essbase accessible data. CVSS 3.1 Base Score 4.3 (Confidentiality impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

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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_