CVE-2026-35603

HIGH

Claude Code: Insecure System-Wide Configuration Loading Enables Local Privilege Escalation on Windows

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2026-35603. PoCs published by jchable.

AI-analyzed exploit summary This repository contains a detection toolkit for the Miasma/Shai-Hulud worm, including IOCs, scanning scripts, and deobfuscation tools. It does not include functional exploit code but provides comprehensive detection and analysis capabilities.

Description

Claude Code is an agentic coding tool. In versions prior to 2.1.75 on Windows, Claude Code loaded the system-wide default configuration from C:\ProgramData\ClaudeCode\managed-settings.json without validating directory ownership or access permissions. Because the ProgramData directory is writable by non-administrative users by default and the ClaudeCode subdirectory was not pre-created or access-restricted, a low-privileged local user could create this directory and place a malicious configuration file that would be automatically loaded for any user launching Claude Code on the same machine. Exploiting this would have required a shared multi-user Windows system and a victim user to launch Claude Code after the malicious configuration was placed. This issue has been fixed on version 2.1.75.

Exploits (1)

nomisec SCANNER
by jchable · poc
https://github.com/jchable/miasma-toolkit

This repository contains a detection toolkit for the Miasma/Shai-Hulud worm, including IOCs, scanning scripts, and deobfuscation tools. It does not include functional exploit code but provides comprehensive detection and analysis capabilities.

Classification
Scanner 95%
Attack Type
Other
Complexity
Moderate
Reliability
Reliable
Target: GitHub repositories and local systems
No auth needed
Prerequisites: PowerShell 7+ · GitHub CLI for remote scanning
mistral-large-3 · analyzed Jun 25, 2026 Full analysis →

References (1)

Core 1
Core References

Scores

CVSS v3 7.3
EPSS 0.0011
EPSS Percentile 1.4%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-426
Status published
Products (3)
anthropic/claude_code < 2.1.75
anthropic-ai/claude-code 0 - 2.1.75npm
anthropics/claude-code < 2.1.75
Published Apr 17, 2026
Tracked Since Apr 18, 2026