---
id: "CVE-2026-91335"
kind: "vulnerability"
aliases: ["CVE-2026-91335"]
title: "Oracle Java SE AWT flaw leaks a subset of data to remote attackers"
severity: "low"
cvss: 2.6
epss: 0.00204
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["desktop-clients", "graalvm", "java", "oracle-jdk", "runtime"]
not_affected_if: ["no-web-start-or-applets", "server-only-trusted-code"]
published_at: "2026-10-20T22:20:35+00:00"
first_seen_at: "2026-10-23T21:57:26+00:00"
updated_at: "2026-10-25T12:38:52+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91335", "first_seen_at": "2026-10-23T21:57:26+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-91335", "first_seen_at": "2026-10-25T12:38:52+00:00"}]
---

# Oracle Java SE AWT flaw leaks a subset of data to remote attackers

A flaw in the AWT component of Oracle Java SE, GraalVM for JDK and GraalVM Enterprise Edition lets a low-privileged attacker read a subset of accessible data. It needs network access, a hard-to-exploit condition and a victim who takes an action, and the advisory says it mainly matters for sandboxed Java Web Start or applet use with untrusted code.

_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 and 27.
- Check for GraalVM for JDK 17.0.20.1 or 21.0.12.1, or GraalVM Enterprise Edition 21.3.19.1.1.
- Check whether Java Web Start or applets are enabled on client machines.

## Fix

- Move Oracle Java SE to a patched release from Oracle's April 2026 Critical Patch Update (the sources do not list the exact fixed versions).
- Move GraalVM for JDK and GraalVM Enterprise Edition to patched builds from Oracle.
- Remove Java Web Start and applet use where they are not needed.

## Timeline

- 2026-10-23T21:57:26+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-91335
- 2026-10-25T12:38:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-91335

## From the sources

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: AWT).  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. Difficult to exploit vulnerability allows low privileged attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition.  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 Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition 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 2.6 (Confidentiality impacts).  CVSS Vector: (CVSS:3.1/AV:N/AC:H/PR:L/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_