CVE-2026-44470

Claude Desktop: Local Privilege Escalation via Directory Junction in CoworkVMService

Published May 13, 2026 CVSS 4.0 · 8.5 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Anthropic
Anthropic claude Desktop
Microsoft
Microsoft windows
CPEs cpe:2.3:a:anthropic:claude_desktop:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*
Vendors & Products Anthropic
Anthropic claude Desktop
Microsoft
Microsoft windows
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
First Time appeared Anthropics
Anthropics claude Code
Vendors & Products Anthropics
Anthropics claude Code
Type Values Removed Values Added
Description 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.
Title Claude Desktop: Local Privilege Escalation via Directory Junction in CoworkVMService
Weaknesses CWE-269
CWE-59
References
Metrics cvssV4_0

{'score': 8.5, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 13, 2026, 6:37 PM
Reserved
May 6, 2026, 5:18 PM
Status
Analyzed
Published
May 13, 2026, 4:16 PM
Modified
Oct 26, 2026, 2:10 PM