Description

In JetBrains IntelliJ IDEA before 2026.3 hTML injection was possible in Remote Development editor tabs

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.7",
  "pubDate": "2026-11-06T17:17:22.550Z",
  "pubdate": "2026-11-06T17:17:22.550Z",
  "executiveSummary": "A vulnerability exists in JetBrains IntelliJ IDEA before version 2026.3, involving improper neutralization of input during web page generation within Remote Development editor tabs. This flaw permits HTML injection, potentially allowing an attacker to inject arbitrary HTML content into the context of the affected editor component.\nThe vulnerability poses a risk of cross-site scripting (XSS) or UI redressing if an attacker can control the content rendered within these tabs. Successful exploitation requires the ability to influence the data processed and displayed by the Remote Development client. The impact includes potential unauthorized actions performed on behalf of the user or the exfiltration of sensitive information displayed within the interface, depending on the client's internal security architecture and sandbox constraints.",
  "technicalDetails": "The vulnerability arises from the insufficient sanitization of data rendered within the Remote Development editor tabs of JetBrains IntelliJ IDEA. In a Remote Development architecture, the IDE client often processes data sent from a remote host or from external sources to populate UI components.\nThe root cause is identified as an improper input validation flaw where user-controlled or externally influenced strings are passed to a web-based rendering engine within the IDE without adequate escaping or HTML entity encoding. When the editor tab component processes this malicious input, it interprets injected tags—such as <script>, <iframe>, or <img> with event handlers—as legitimate HTML markup rather than plain text.\nThe attack flow commences when an attacker identifies a vector to supply malformed input that will be subsequently rendered by the IntelliJ IDEA Remote Development client. This could involve manipulating project configuration files, workspace settings, or collaborative session metadata that the IDE interface consumes. Once the malicious payload reaches the client, the UI component renders the injected HTML in the document object model (DOM) of the tab.\nBecause the rendered content operates within the trust context of the IDE's UI framework, successful injection allows an attacker to execute JavaScript code. This code can perform actions such as accessing local environment variables accessible to the UI process, capturing user input via keylogging overlays, or facilitating CSRF-like attacks against the IDE's internal services. The scope of exploitation is limited by the specific security boundaries and context isolation implemented by the JetBrains IDE's rendering engine. Affected versions include all releases of IntelliJ IDEA prior to 2026.3. The vulnerability does not necessarily require local authentication on the remote host if the injection vector is triggered through external project metadata or shared configuration files."
}