Description

In JetBrains IntelliJ IDEA before 2026.3 command execution was possible via control characters in terminal command completion

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.3",
  "pubDate": "2026-11-06T17:17:23.560Z",
  "pubdate": "2026-11-06T17:17:23.560Z",
  "executiveSummary": "A command execution vulnerability exists in JetBrains IntelliJ IDEA prior to version 2026.3, stemming from improper handling of control characters during terminal command completion.\nThe vulnerability allows for arbitrary command execution by leveraging specific escape sequences or control characters within the command completion mechanism.\nSuccessful exploitation enables an attacker to execute arbitrary commands with the privileges of the IntelliJ IDEA process, potentially leading to full system compromise.\nThis vulnerability affects versions of IntelliJ IDEA released before 2026.3.\nExploitation typically requires user interaction, such as triggering an autocomplete operation within the IDE's built-in terminal or related features.\nThe risk is significant as it bridges the gap between IDE functionality and underlying OS command execution without adequate input sanitization.",
  "technicalDetails": "The vulnerability originates from the terminal integration within IntelliJ IDEA failing to properly sanitize or filter control characters when processing command completion suggestions.\nWhen a user invokes command completion in the terminal, the application fetches potential candidates. If these candidates or the context in which they are presented contain malicious control characters (e.g., ANSI escape sequences or shell-specific delimiters), the terminal emulator may inadvertently interpret these characters as commands or arguments rather than literal strings.\nThe attack flow involves an attacker influencing the environment or configuration files that populate command completion suggestions. By injecting crafted control characters into these sources, an attacker causes the IDE's terminal process to prematurely terminate the intended command and execute a secondary, unauthorized command injected via the completion stream.\nBecause the terminal emulator operates within the IDE's execution context, the injected payload executes with the same user privileges and system access as the IDE itself.\nThe vulnerability leverages the way terminal emulators interpret input buffers. By injecting characters such as carriage returns or newline sequences, an attacker can manipulate the command buffer to execute commands even if the initial command completion process was intended to be non-executable.\nThis behavior facilitates arbitrary command execution, bypassing typical user-input expectations within the terminal window. Once triggered, the attacker's payload executes immediately, enabling lateral movement or further exploitation within the development environment.\nThe flaw highlights a failure in input validation where data meant for display or selection is treated as executable input by the terminal's command parser.\nAuthentication is not strictly required to trigger the vulnerability if the environment is already accessible to the attacker, but the primary constraint is the triggering of the specific autocomplete function within the IDE."
}