---
id: CVE-2026-91479
title: Vulnerability in the RDBMS component of Oracle Database Server
summary: >-
  Vulnerability in the RDBMS component of Oracle Database Server.  Supported
  versions that are affected are 23.4.0-23.26.3. Easily exploitable
  vulnerability allows unauthenticated attacker with access to the physical
  communication segment …
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
vendor: Oracle Corporation
product: Oracle Database Server
affected:
  - oracle_database_server >= 23.4.0 <= 23.26.3
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T21:26:10.802Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-91479'
references:
  - url: 'https://www.oracle.com/security-alerts/cpuoct2026.html'
    label: Oracle Advisory
tags:
  - cve.org
ingestedAt: '2026-10-20T22:23:33.744Z'
---

## Overview

Vulnerability in the RDBMS component of Oracle Database Server.  Supported versions that are affected are 23.4.0-23.26.3. Easily exploitable vulnerability allows unauthenticated attacker with access to the physical communication segment attached to the hardware where the RDBMS executes to compromise RDBMS.  Successful attacks of this vulnerability can result in unauthorized ability to cause a hang or frequently repeatable crash (complete DOS) of RDBMS. CVSS 3.1 Base Score 6.5 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

## Affected

- `oracle_database_server >= 23.4.0 <= 23.26.3`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.