---
id: "CVE-2026-87294"
kind: "vulnerability"
aliases: ["CVE-2026-87294"]
title: "Oracle Java SE: network attacker can read and change some data"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["graalvm", "java", "java-web-services", "jdk", "runtime", "self-hosted"]
not_affected_if: ["no-network-exposed-java", "patched-jdk"]
published_at: "2026-10-20T22:20:06+00:00"
first_seen_at: "2026-10-23T21:57:25+00:00"
updated_at: "2026-10-25T03:51:30+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-87294", "first_seen_at": "2026-10-23T21:57:25+00:00"}]
---

# Oracle Java SE: network attacker can read and change some data

A flaw in the Security component of Oracle Java SE and GraalVM lets an unauthenticated attacker over the network modify and read a subset of accessible data. The description notes it can be reached through APIs fed by a web service and also affects sandboxed Java Web Start and applet deployments.

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

## How to check

- Run `java -version` and compare the output against the affected builds listed in the Oracle advisory (for example `8u503`, `11.0.32.1`, `17.0.20.1`, `21.0.12.1`, `25.0.4.1`).
- For GraalVM, run `native-image --version` or `java -version` and check for `17.0.20.1`, `21.0.12.1` or `21.3.19.1.1`.

## Fix

- Update Oracle Java SE to a patched release from the Oracle Critical Patch Update that fixes CVE-2026-87294; the exact fixed builds are unknown from these sources.
- Update Oracle GraalVM for JDK and GraalVM Enterprise Edition to the patched release named in the Oracle advisory; unknown from these sources.

## Timeline

- 2026-10-23T21:57:25+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-87294

## From the sources

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Security).  Supported versions that are affected are Oracle Java SE: 8u503, 8u503-perf, 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1, 27;    Oracle GraalVM for JDK: 17.0.20.1 and  21.0.12.1;   Oracle GraalVM Enterprise Edition: 21.3.19.1.1. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition.  Successful attacks of this vulnerability can result in  unauthorized update, insert or delete access to some of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data as well as  unauthorized read access to a subset of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition accessible data. 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 6.5 (Confidentiality and Integrity impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N).

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_