---
id: "CVE-2026-91634"
kind: "vulnerability"
aliases: ["CVE-2026-91634"]
title: "Oracle Essbase: unauthenticated network attacker can read a subset of data"
severity: "medium"
cvss: 5.3
epss: 0.00251
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: ["unknown"]
published_at: "2026-10-20T22:21:03+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T04:22:28+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91634", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91634", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# Oracle Essbase: unauthenticated network attacker can read a subset of data

Oracle Essbase version 21.8.3.0.0 has a Security component flaw reachable over T3 and IIOP. An unauthenticated attacker with network access can read a subset of data Essbase can access.

_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 against `21.8.3.0.0` in the Oracle Essbase deployment or admin console.
- Check whether T3 or IIOP listeners are reachable from untrusted networks; the sources do not name a config file or setting.

## Fix

- Apply the Oracle Critical Patch Update for Essbase that addresses this CVE; the fixed version is unknown from the sources.

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91634
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91634

## 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 unauthenticated attacker with network access via T3, IIOP 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 5.3 (Confidentiality impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/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_