---
id: "CVE-2026-91651"
kind: "vulnerability"
aliases: ["CVE-2026-91651"]
title: "Oracle Essbase: Web Platform flaw lets low-privileged users take over server"
severity: "high"
cvss: 8.5
epss: 0.003
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: ["default-config"]
published_at: "2026-10-20T22:21:05+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T03:00:23+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91651", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91651", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# Oracle Essbase: Web Platform flaw lets low-privileged users take over server

Oracle Essbase's Web Platform component has a flaw that a low-privileged user can reach over HTTP. Successful exploitation can take over the Essbase server and affect other products through scope change.

_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

- Check the installed Essbase version against `21.8.3.0.0`
- unknown

## Fix

- Move Oracle Essbase off `21.8.3.0.0` to the fixed release listed in Oracle's Critical Patch Update advisory
- unknown

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91651
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91651

## From the sources

Vulnerability in Oracle Essbase (component: Essbase Web Platform).   The supported version that is affected is 21.8.3.0.0. Difficult to exploit 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 takeover of Oracle Essbase. CVSS 3.1 Base Score 8.5 (Confidentiality, Integrity and Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H).

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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_