---
id: "CVE-2026-91477"
kind: "vulnerability"
aliases: ["CVE-2026-91477"]
title: "Oracle JavaFX: unauthenticated network attacker can read a subset of data"
severity: "low"
cvss: 3.1
epss: 0.00228
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["desktop-clients", "java", "javafx", "runtime"]
not_affected_if: ["no-javafx", "server-only-java", "trusted-code-only"]
published_at: "2026-10-20T22:20:51+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T12:38:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91477", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91477", "first_seen_at": "2026-10-25T12:38:51+00:00"}]
---

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

Oracle JavaFX versions 25.0.4 and 27 have a flaw that lets an unauthenticated attacker over the network read a subset of data the library can access. Exploitation is hard and needs a user to act, and the note says it applies mainly to clients running untrusted sandboxed Java Web Start or applet code.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `java -version` and check the JavaFX version bundled or on the classpath against `25.0.4` and `27`
- Check whether any sandboxed Java Web Start or applet code loads untrusted content on client machines

## Fix

- Move JavaFX to a patched release listed in Oracle's Critical Patch Update for the affected version (exact fixed version: unknown)

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91477
- 2026-10-25T12:38:51+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91477

## From the sources

Vulnerability in the Oracle JavaFX product of Oracle Java SE (component: JavaFX).  Supported versions that are affected are Oracle JavaFX: 25.0.4 and  27. Difficult to exploit vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle JavaFX.  Successful attacks require human interaction from a person other than the attacker. Successful attacks of this vulnerability can result in  unauthorized read access to a subset of Oracle JavaFX accessible data. Note: This vulnerability 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. This vulnerability does not apply to Java deployments, typically in servers, that load and run only trusted code (e.g., code installed by an administrator). CVSS 3.1 Base Score 3.1 (Confidentiality impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/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_