External risk intelligence

IntelliJ IDEA Code Injection via UI Designer Form Files.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-64815

IntelliJ IDEA is an integrated development environment (IDE) used locally by developers. It is a client-side desktop application, not a server, service, or internet-facing appliance. UI Designer form files are used for local development and are not typically exposed to the public internet.

Code Injection

Jetbrains Intellij Idea

before 2026.2

Halo Surface Signal: 1 out of 5 — much less likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A critical vulnerability in JetBrains IntelliJ IDEA could allow attackers to inject and execute arbitrary code through UI Designer form files. While the vulnerability itself is severe, its potential impact on our organization is currently assessed as very unlikely due to the nature of IntelliJ IDEA as a local developer tool not typically exposed to external networks. The primary concern is to confirm if our development environments are potentially exposed and if the affected version is in use.

Code injection possible via design files.
Developers use this tool locally.
Confirm exposure and usage of affected versions.

Attack Path

How an attacker could exploit the issue

An attacker could inject malicious code by manipulating UI Designer form files within IntelliJ IDEA. This vulnerability doesn't require special privileges or user interaction, as it's accessible over the network and can lead to full system compromise.

No authentication or user interaction needed.
Malicious form files trigger injection.
Leads to arbitrary code execution.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, this vulnerability could allow arbitrary code injection through UI Designer form files, potentially impacting the integrity and availability of the development environment.

Development environment code integrity.
Via UI Designer form files.
Unauthorized code execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

Real-world ownership of this vulnerability likely falls to teams managing developer tools and the software development lifecycle, such as platform engineering or application development leads. The immediate first step is to confirm the presence and scope of affected IntelliJ IDEA installations within the organization, determine business criticality and exposure, and identify the specific owners of these development environments before planning remediation activities.

Own the issue: Application development or platform teams.
Verify first: Identify affected installations and owners.
Action: Plan remediation based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is JetBrains IntelliJ IDEA?

IntelliJ IDEA is a comprehensive integrated development environment (IDE) built by JetBrains. Developers use it to write, debug, and manage code for various programming languages. It includes built-in tools for designing user interfaces, such as the UI Designer, which allows users to create graphical layouts using form files that define the structure and appearance of software applications.

What does CVE-2026-64815 mean by code injection?

This vulnerability is classified as CWE-94, or Improper Control of Generation of Code. It means the software does not properly filter or validate input within UI Designer form files. Because of this weakness, an attacker could supply specially crafted content that the application mistakenly treats as executable commands, leading to unauthorized code execution on the system running the IDE.

How is this vulnerability triggered?

The flaw is triggered when the IDE processes a manipulated UI Designer form file. This does not require the attacker to have special system privileges or wait for a user to perform a specific action. However, simply having the software installed is not enough; the system must specifically parse a malicious or untrusted form file to initiate the injection process.

Do I need to worry about this if I use IntelliJ IDEA?

While the vulnerability is technically critical, Halo Surface Signal notes it is very unlikely to pose a broad risk. IntelliJ IDEA is primarily a desktop application used locally by developers, not a public-facing server or service. Since these form files are typically used in private development workflows rather than exposed on the public internet, the practical opportunity for an external attacker to exploit this is generally limited.

What should I do if I use an affected version?

The most important first step is to inventory your development environments to see if you are running a version of IntelliJ IDEA earlier than 2026.2. Once you have identified any affected installations, coordinate with your development or platform engineering teams to plan for an upgrade. Focus on confirming which developers are currently using the tool so you can manage the update process without disrupting active projects.

References

www.jetbrains.com/privacy-security/issues-fixed/

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.