What is the CVSS score of CVE-2026-91634?

CVE-2026-91634 has a CVSS 3.1 base score of 5.3 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N. EPSS exploitation probability: 0.3%.

Oracle Essbase CVE-2026-91634

EUVD-2026-106821 MEDIUM

Information Exposure (CWE-200)

2026-10-20 secalert_us@oracle.com

GHSA-53f6-v5rf-v7xc

Information Disclosure Oracle Essbase

5.3

CVSS 3.1 · Vendor: oracle

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Reach exposed T3/IIOP listener
Exploit

Send crafted unauthenticated request
Impact

Read subset of Essbase data

Vulnerability Assessment

Weakness	CWE CWE-200 OWASP Top 10:2025 A01:2025 - Broken Access Control ASVS 5.0 V14 - Data Protection Data exposure prevention MITRE ATT&CK 2 techniques across 2 tactics: Collection, Discovery The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	Exploitation requires network access to the Oracle Essbase server's T3 and/or IIOP protocol listeners (the WebLogic-based remote invocation protocols), against the affected supported version 21.8.3.0.0. No authentication, privileges, or user interaction are required (PR:N/UI:N), and default configurations are exploitable per the description. The primary limiting factors are network exposure of the T3/IIOP interfaces - these are frequently restricted to internal management networks or filtered by firewalls/connection filters as an Oracle hardening best practice - and the bounded impact, which is read access to only a subset of accessible data with no integrity or availability effect.
Impact	This is a moderate-severity confidentiality issue (CVSS 3.1 base 5.3) rather than a top-tier priority. The CVSS vector (AV:N/AC:L/PR:N/UI:N) confirms a network-reachable, low-complexity, unauthenticated attack, which raises concern, but the impact is deliberately limited: C:L with I:N and A:N means only unauthorized read access to a subset of Essbase data, with no integrity or availability impact. No EPSS score, CISA KEV listing, or public POC is present in the provided data, so there is no evidence of active or imminent widespread exploitation - the exploitation signal relies solely on the theoretical ease of the CVSS vector. The input Tag 'Authentication Bypass' conflicts with the actual data: the description and CVSS describe an unauthenticated information-disclosure flaw (read access), not a privilege/authentication bypass granting integrity impact - treat that tag with skepticism and verify against Oracle's advisory. Overall: a real but bounded issue worth patching in the normal Oracle CPU cycle, not an emergency, absent any KEV/EPSS escalation.
Exploit ScenarioDerived	An attacker with network reachability to the Essbase server's T3 or IIOP (WebLogic remote protocol) listeners sends crafted requests that exploit the Security component flaw without authenticating. This grants read access to a subset of Essbase data (e.g., metadata or stored values). No public exploit code is identified at time of analysis, so exploitation would currently require independent development.

This Month Plan within 30 days. Why: MEDIUM severity (CVSS 4.0-6.9).

No patch listed yet 0.3% exploitation probability (EPSS)

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AnalysisAIv1 – Oct 20, 2026

Oracle Essbase 21.8.3.0.0 exposes a confidentiality weakness through its WebLogic-based T3 and IIOP remote invocation listeners, letting network-reachable attackers bypass authentication and read a subset of the data the Essbase server can access. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N, base 5.3) confirms no credentials or user interaction are needed, but impact is bounded to partial confidentiality with no integrity or availability effect. This is a moderate-severity issue rather than a top-tier priority; no public exploit code or confirmed active exploitation (CISA KEV) is identified in the available data, and exploitation depends on T3/IIOP being exposed rather than restricted to internal management networks.

RemediationAI

Apply the Oracle Critical Patch Update fix for the October 2026 cycle, following the guidance in https://www.oracle.com/security-alerts/cpuoct2026.html; Oracle CPU advisories typically specify the minimum patched bundle for each affected version, so confirm the exact Essbase 21.8.x bundle level named there before closing the item, and treat any assertion of a specific build number as unverified until matched against that advisory. If patching must be staged, reduce exposure first by removing T3 and IIOP reachability from untrusted networks: restrict the listeners to internal management subnets with firewall ACLs, and enable WebLogic connection filters (weblogic.security.net.ConnectionFilterImpl) to allow only known hosts to the T3/IIOP ports. The trade-off is that connection filters and ACLs break legitimate remote clients, JNDI lookups, and cluster or administration traffic sourced from unexpected addresses, so inventory clients before enforcing them and test filter rules in a staging environment. Where the T3 protocol is not required at all, disabling the T3 listener entirely and relying on HTTP(S) management channels eliminates the primary attack path, at the cost of incompatible tooling that depends on T3. Monitor for anomalous pre-authentication requests to T3/IIOP ports while remediation is in progress, and validate that no public exploit code has appeared for this CVE before relaxing compensating controls.

Affected VersionsENISA

Oracle Essbase 21.8.3.0.0

Affected Packages

euvd oracle_essbase no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Oracle Essbase is an OLAP/multidimensional analytics server, and the affected 21.8.x line runs atop Oracle WebLogic Server infrastructure, so its remote-invocation surface includes the T3 and IIOP/RMI protocols used for Java-to-Java object communication. Those protocols deserialize and dispatch remote calls, and they have historically been the entry point for Oracle middleware pre-authentication bypasses, where a crafted request reaches server-side logic before any authentication check is enforced. The supplied data carries no CWE mapping, so the precise root-cause class is unconfirmed; operationally it behaves as an authentication-bypass-class defect in the Security component that grants read-only visibility into a subset of Essbase-accessible data. Because the scope is unchanged (S:U) and only confidentiality is affected (C:L, I:N, A:N), the flaw is an information-disclosure primitive rather than a path to code execution or data modification. The main environmental variable is reachability: T3 and IIOP are commonly bound to internal management segments or blocked by WebLogic connection filters and network ACLs, which reduces practical exposure even though the vector is scored network-exploitable with no privileges.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (oracle) PRIMARY 5.3 MEDIUM

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

vuln.today AI 5.3 MEDIUM

Unauthenticated network exploitation over T3/IIOP (AV:N/AC:L/PR:N/UI:N) yielding partial read access only, so C:L with I:N and A:N.

3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Primary rating from Vendor (oracle).

CVSS VectorVendor: oracle

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

DescriptionCVE.org

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).

Threat Intelligence Overview

EPSS Score

0.3%

Top 84% exploitable

Prevalence

Medium

enterprise OLAP/BI database, common in finance but not everywhere

Data Quality

4 sources

Confidence: Medium

EUVD

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity MEDIUM

CISA KEV No

Public POC No

EPSS 0.3%

Patch available No

Active threat No

Deciding rule

MEDIUM severity (CVSS 4.0-6.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact· derived

Medium

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +26

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.