Cloudanix VulnDB

CVE-2026-91418

Medium · 5.3

CVSS

5.3

EPSS

0.4%

Published

Oct 20, 2026

CISA due date

—

Cloudanix analysis

Monitor only SSVC: Track

A problem in how Java handles certain images can let remote attackers briefly disrupt parts of applications that process those images.

Exploitation
Remote Unauthenticated
Attacker needs
None
Complexity
Low
Impact
Denial Of Service
Component
Library
Class
Denial of service
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

The flaw in the ImageIO component permits an unauthenticated network attacker to supply crafted image data via exposed APIs, resulting in partial denial of service that impairs availability without affecting confidentiality or integrity.

Why it matters to the business

Java-based applications handling images may experience temporary unresponsiveness or degraded performance when processing external data, potentially disrupting services that rely on image parsing and increasing operational overhead until mitigated.

How an attack unfolds

An attacker identifies a reachable Java endpoint or service that invokes ImageIO APIs, crafts a malicious image payload designed to trigger the vulnerability, and transmits it over supported network protocols, causing partial resource exhaustion or service degradation in the affected component.

How to fix it

Apply the latest Oracle Critical Patch Update that addresses this issue in the affected Java SE, JavaFX, and GraalVM releases. Monitor Oracle advisories for fixed versions and deploy updates across all installations, including client-side sandboxed deployments.

How to confirm the fix worked

Verify installed Java versions against the latest Oracle security updates, perform regression testing with image-processing workloads, and confirm that partial DoS conditions no longer occur under equivalent network input scenarios.

Typical attack path

  1. Locate a target application or service exposing Java ImageIO functionality over the network
  2. Prepare a specially crafted image file or data stream
  3. Deliver the payload to the ImageIO API via HTTP, web service, or other supported protocol
  4. Trigger processing to induce partial denial of service

How to detect it

Monitor Java process logs and crash reports for unexpected ImageIO-related exceptions or partial service failures when handling external image data; correlate with network traffic containing unusual image payloads.

What your security team should do

  • Prioritize deployment of Oracle security patches to all affected Java runtimes within the next maintenance window
  • Restrict unnecessary network exposure of services that invoke ImageIO APIs
  • Implement input validation or sandboxing around image processing code paths where feasible
  • Review and harden Java Web Start or applet deployments that process untrusted content

The record

Vulnerability in the Oracle Java SE, Oracle JavaFX, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: ImageIO). 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 JavaFX: 21.0.12, 25.0.4, 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 JavaFX, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Oracle Java SE, Oracle JavaFX, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. 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 5.3 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

Affected packages

Ecosystem Package Introduced Fixed

Related vulnerabilities