---
id: "CVE-2026-91452"
kind: "vulnerability"
aliases: ["CVE-2026-91452"]
title: "Oracle Java SE: networking flaw lets unauthenticated attackers alter some data"
severity: "medium"
cvss: 5.3
epss: 0.00282
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["graalvm", "java", "oracle-jdk", "runtime", "self-hosted"]
not_affected_if: ["no-untrusted-network-input", "not-using-affected-version"]
published_at: "2026-10-20T22:20:48+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T12:38:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91452", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91452", "first_seen_at": "2026-10-25T12:38:52+00:00"}]
---

# Oracle Java SE: networking flaw lets unauthenticated attackers alter some data

A flaw in the Networking component of Oracle Java SE and GraalVM lets a remote, unauthenticated attacker who can send data to an exposed API change or delete some accessible data. Oracle rates it CVSS 5.3 with integrity impact only, and it requires no user action beyond the attacker supplying data to the affected API.

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

## How to check

- Run `java -version` and compare against the affected releases: 8u503, 11.0.32.1, 17.0.20.1, 21.0.12.1, 25.0.4.1, 27
- For GraalVM, check `native-image --version` against 17.0.20.1, 21.0.12.1 or 21.3.19.1.1
- Confirm whether a service exposes the Java Networking APIs to untrusted input, such as a web service

## Fix

- Upgrade Oracle Java SE to the patched release from Oracle's April 2026 Critical Patch Update (exact fixed versions unknown from the sources)
- Upgrade Oracle GraalVM for JDK and GraalVM Enterprise Edition to the patched release from the same update

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91452
- 2026-10-25T12:38:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91452

## From the sources

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: Networking).  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. Note: This vulnerability can only be exploited by supplying data to APIs in the specified Component without using Untrusted Java Web Start applications or Untrusted Java applets, such as through a web service. CVSS 3.1 Base Score 5.3 (Integrity impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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_