---
id: CVE-2026-91409
title: 'Vulnerability in Oracle Java SE (component: Networking)'
summary: >-
  Vulnerability in Oracle Java SE (component: Networking).   The supported
  version that is affected is Oracle Java SE: 27. Difficult to exploit
  vulnerability allows unauthenticated attacker with network access via multiple
  protocols to com…
severity: low
cvss: 3.7
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'
cvssSource: cna
vendor: Oracle Corporation
product: Oracle Java SE
affected:
  - oracle_java_se 27
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T21:25:48.786Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-91409'
references:
  - url: 'https://www.oracle.com/security-alerts/cpuoct2026.html'
    label: Oracle Advisory
tags:
  - cve.org
ingestedAt: '2026-10-20T22:23:33.764Z'
---

## Overview

Vulnerability in Oracle Java SE (component: Networking).   The supported version that is affected is Oracle Java SE: 27. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE.  Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Oracle Java SE. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 3.7 (Availability impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L).

## Affected

- `oracle_java_se 27`

## Remediation

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