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CVE-2025-52882VulnerabilityPublished

CVE-2025-52882: anthropics claude-code · Missing Origin Validation in WebSockets

Affects anthropics claude-codeSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High : upgrade to 1.0.24 soon.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 29% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 1.0.24
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

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 24 Jun 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Upgrade anthropics/claude-code to 1.0.24.

Affected software

ProductAffectedFixed in
GitHubanthropics/claude-codepkg:github/anthropics/claude-codeOther threatsAffected
  • >=0.2.116 <1.0.24
Fixed in
  • 1.0.24

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Immediate action should be to verify the versions of Claude Code extensions installed in all developer IDEs (VSCode, Cursor, Windsurf, VSCodium, IntelliJ, PyCharm, Android Studio). 2. Update the Claude Code for VSCode extension to version 1.0.24 or later and the JetBrains Claude Code [Beta] plugin to version 0.1.9 or later. If updates are not feasible immediately, uninstall the vulnerable extensions to eliminate exposure. 3. Restart the IDE after updating or uninstalling to ensure the patch takes effect. 4. Implement network-level controls to restrict outbound WebSocket connections from developer machines to untrusted domains, reducing the risk of unauthorized connections initiated by malicious webpages. 5. Educate developers about the risks of visiting untrusted websites while working in their IDEs, especially when using extensions that interact with external services. 6. Monitor IDE logs and network traffic for unusual WebSocket connections or file access patterns that could indicate exploitation attempts. 7. For organizations using Jupyter Notebooks within VSCode, enforce policies to avoid accepting prompts from untrusted sources and consider disabling notebook features if not required. 8. Incorporate vulnerability scanning and patch management processes specifically targeting development tools and their extensions to ensure timely updates in the future.

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.

References

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