Description

In JetBrains IntelliJ IDEA before 2026.3 arbitrary file write was possible via symlinks when extracting plugin archives

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.1",
  "pubDate": "2026-11-06T17:17:22.833Z",
  "pubdate": "2026-11-06T17:17:22.833Z",
  "executiveSummary": "A critical vulnerability exists in JetBrains IntelliJ IDEA, occurring prior to version 2026.3, related to the insecure extraction of plugin archives.\nThe vulnerability is classified as an Arbitrary File Write, which allows a malicious actor to overwrite files on the host filesystem by leveraging symbolic links (symlinks) within a crafted plugin package.\nAn attacker can exploit this flaw by distributing a malicious plugin archive; once the IDE processes the extraction of this archive, it fails to properly sanitize file paths contained within the package.\nSuccessful exploitation results in unauthorized file modification, which can lead to Remote Code Execution (RCE), privilege escalation, or the corruption of critical system configurations depending on the permissions of the IDE process.\nThis vulnerability poses a significant risk to the integrity and security of the developer's environment, as the IDE often operates with the user's full local privileges.\nThe primary requirement for exploitation is the successful delivery and installation of a manipulated plugin archive, bypassing standard input validation mechanisms during the extraction phase.",
  "technicalDetails": "The root cause of the vulnerability resides in the archive extraction logic implemented within the plugin management system of JetBrains IntelliJ IDEA. During the processing of plugin packages (typically compressed archives), the application fails to perform adequate path validation on files contained within the archive header.\nSpecifically, the extraction process is susceptible to symlink attacks, also known as 'ZipSlip' style vulnerabilities. If an attacker crafts an archive entry that points to a symbolic link, or uses directory traversal characters (e.g., ../) in the file path, the IDE may resolve these paths outside of the intended installation directory during the extraction routine.\nWhen the IDE extracts these entries, it fails to detect or neutralize the symlinks that redirect file writes to sensitive locations on the disk. Consequently, the filesystem driver follows the malicious path defined in the archive, allowing the attacker to write arbitrary content to arbitrary locations within the context of the user running the IDE.\nThe attack flow proceeds as follows: First, the attacker creates a malicious plugin archive containing a file with a relative path or a symbolic link designed to target sensitive files, such as startup scripts, configuration files (e.g., .ssh/authorized_keys, .bashrc, or IDE configuration files), or application binaries. Second, the user initiates the installation of this plugin, either manually or via a malicious repository link. Third, the IDE's extraction function initiates the decompression process, blindly trusting the path information provided by the archive metadata. Finally, the file writing operation is redirected via the symlink, resulting in the overwrite or creation of a target file chosen by the attacker.\nThis vulnerability is particularly severe because the payload behavior is unrestricted by the IDE's internal sandbox. Since the extraction logic executes with the permissions of the host user account, the malicious actor effectively gains the ability to modify any file that the user has permission to access. Post-exploitation, this often leads to persistent RCE by overwriting environment startup scripts or injecting malicious code into the IDE's own functional components. Authentication requirements for this attack are minimal, as the entry point is the plugin installation flow, which is a standard administrative task within the IDE."
}