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Claude DesktopApplication · Anthropic

CVE-2026-44470

HIGH · 7.8 CVSS v3.1 Published 2026-05-13
Fix available
A fix is available. Upgrade to 1.3834.0 or later.
See remediation →
80/100
Remediation priority · High
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The Claude Desktop app gives you Claude Code with a graphical interface built for running multiple sessions side by side. Prior to 1.3834.0, the CoworkVMService component in Claude Desktop for Windows ran as SYSTEM and did not validate whether the VM bundle directory was a real directory or an NTFS directory junction before creating files within it. A local non-elevated user could replace the user-writable VM bundle directory with a directory junction pointing to an attacker-chosen location, causing the service to create a SYSTEM-owned file in an arbitrary directory. This could be leveraged for local privilege escalation. This vulnerability is fixed in 1.3834.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Local privilege escalation vulnerability in Claude Desktop's CoworkVMService (versions prior to 1.3834.0) on Windows. The service runs as SYSTEM and fails to validate whether the user-writable VM bundle directory is a real directory or an NTFS directory junction before creating files. A local non-elevated attacker can replace the VM bundle directory with a directory junction pointing to an arbitrary location, causing the SYSTEM-owned service to create files in attacker-controlled locations.

MitigationUpgrade Claude Desktop to version 1.3834.0 or later to obtain the fix that validates directory types before file operations.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Claude DesktopApplication
Affected:< 1.3834.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Claude Desktop is installed
    Check for Claude Desktop installation directory or in Add/Remove Programs
    Affected if Claude Desktop is installed and version cannot be determined or is below 1.3834.0
  2. Check installed Claude Desktop version
    Locate Claude Desktop executable and query its version (typically via file properties or --version flag)
    Affected if The installed version is earlier than 1.3834.0
  3. Identify CoworkVMService
    Open Windows Services management console (services.msc) and locate the CoworkVMService, or run 'sc query CoworkVMService'
    Affected if The CoworkVMService exists and runs under the SYSTEM account (Log On As shows LocalSystem)
  4. Locate VM bundle directory
    Examine service configuration or Claude Desktop data directories to find the path to the VM bundle storage location
    Affected if The VM bundle directory path is writable by a non-elevated user and is located in a user-accessible location
  5. Check if VM bundle directory is a junction
    Use 'fsutil reparsepoint query <directory_path>' or check with 'dir /aL' command to see if the directory is an NTFS reparse point or junction
    Affected if The VM bundle directory is actually a directory junction (reparse point) pointing to an alternate location, allowing an attacker to redirect file creation

A user is affected if Claude Desktop version is below 1.3834.0, the CoworkVMService runs as SYSTEM, and the VM bundle directory is a writable location that could be replaced with a directory junction by a local attacker.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 1.3834.0 or later
Fixed in 1.3834.0
Interim mitigation

Upgrade Claude Desktop to version 1.3834.0 or later to obtain the fix that validates directory types before file operations.

Recommended fix High confidence

Claude Desktop 1.3834.0 or later

  1. 1. Ensure you have a backup of your Claude Desktop configuration if needed.
  2. 2. Download Claude Desktop version 1.3834.0 or later from the official Anthropic website or GitHub releases.
  3. 3. Uninstall the current version of Claude Desktop from your Windows system.
  4. 4. Install the updated Claude Desktop version 1.3834.0 or later.
  5. 5. Verify the installation was successful by checking the installed version in the application settings.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Claude Desktop Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-44470 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data