CVE-2025-52882
Claude Code IDE extensions allow websocket connections from arbitrary origins
In short
Claude Code extensions for popular code editors (VSCode, Cursor, JetBrains IDEs) allow attackers to connect to them from malicious websites without permission. This could let attackers read your files, see what you're working on, or run code if you're using Jupyter Notebooks.
Technical detail
The vulnerability exists due to insufficient origin validation on WebSocket connections in Claude Code extensions (VSCode 0.2.116–1.0.23, JetBrains 0.1.1–0.1.8). An attacker can establish unauthorized WebSocket connections by hosting a malicious webpage that the user visits. In VSCode variants, this enables arbitrary file read, IDE state inspection, and code execution in Jupyter contexts; in JetBrains, attackers gain access to selection events, open file lists, and syntax error data.
Summary generated and translated by AI from the official description.
Claude Code is an agentic coding tool. Claude Code extensions in VSCode and forks (e.g., Cursor, Windsurf, and VSCodium) and JetBrains IDEs (e.g., IntelliJ, Pycharm, and Android Studio) are vulnerable to unauthorized websocket connections from an attacker when visiting attacker-controlled webpages. Claude Code for VSCode IDE extensions versions 0.2.116 through 1.0.23 are vulnerable. For Jetbrains IDE plugins, Claude Code [beta] versions 0.1.1 through 0.1.8 are vulnerable. In VSCode (and forks), exploitation would allow an attacker to read arbitrary files, see the list of files open in the IDE, get selection and diagnostics events from the IDE, or execute code in limited situations where a user has an open Jupyter Notebook and accepts a malicious prompt. In JetBrains IDEs, an attacker could get selection events, a list of open files, and a list of syntax errors. Claude released a patch for this issue on June 13th, 2025. Although Claude Code auto-updates when a user launch it and auto-updates the extensions, users should take the following steps, though the exact steps depend on one's integrated development environment (IDE). For VSCode, Cursor, Windsurf, VSCodium, and other VSCode forks, check the extension Claude Code for VSCode. Open the list of Extensions (View->Extensions), look for Claude Code for VSCode among installed extensions, update or uninstall any version prior to 1.0.24, and restart the IDE. For JetBrains IDEs including IntelliJ, PyCharm, and Android Studio, check the plugin Claude Code [Beta]. Open the Plugins list, look for Claude Code [Beta] among installed extensions, update or uninstall any version prior to 0.1.9, and restart the IDE.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N