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Claude CodeApplication · Anthropic

CVE-2026-35603

HIGH · 7.3 CVSS v3.1 Published 2026-04-17
Fix available
A fix is available. Upgrade to 2.1.75 or later.
See remediation →
73/100
Remediation priority · Elevated

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
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.

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

Claude Code versions prior to 2.1.75 on Windows load a system-wide configuration file from C:\ProgramData\ClaudeCode\managed-settings.json without validating directory ownership. Since the ProgramData directory is writable by non-administrative users by default and Claude Code did not pre-create or protect this subdirectory, a low-privilege local attacker could create the directory and place a malicious configuration file that would execute for all users launching Claude Code on the system.

MitigationUpgrade Claude Code to version 2.1.75 or later. On shared multi-user systems, verify that no unauthorized configuration files exist in C:\ProgramData\ClaudeCode\ and consider implementing access controls on that directory.

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 CodeApplication
Affected:< 2.1.75

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
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/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. Check if Claude Code is installed on Windows
    Look for Claude Code installation in common locations: C:\Program Files\Claude Code\, or check Start Menu for Claude Code, or look in C:\Users\%USERNAME%\AppData\Local\Programs\Claude Code\
    Affected if Claude Code is not installed - not vulnerable. If installed, continue to version check.
  2. Determine installed Claude Code version
    Run 'Claude Code --version' or 'claude --version' from Command Prompt or PowerShell, or check the version in the executable properties (right-click claude.exe → Properties → Details → File version)
    Affected if Version is less than 2.1.75 - potentially vulnerable. Continue to directory check.
  3. Verify the vulnerable configuration directory exists
    Open File Explorer and navigate to C:\ProgramData\ClaudeCode\ or run 'dir C:\ProgramData\ClaudeCode' in Command Prompt
    Affected if The directory C:\ProgramData\ClaudeCode\ does NOT exist - not vulnerable (prerequisite for exploit is missing). If directory EXISTS, continue to file check.
  4. Check for the managed-settings.json configuration file
    Run 'dir C:\ProgramData\ClaudeCode\managed-settings.json' or manually check if the file exists in that directory
    Affected if The file managed-settings.json does NOT exist - not vulnerable (exploit requires this file). If file EXISTS, check permissions.
  5. Inspect directory and file permissions
    Right-click the ClaudeCode folder in ProgramData, go to Properties → Security tab. Check if non-admin users have Write or Modify permissions. Or run 'icacls C:\ProgramData\ClaudeCode'
    Affected if Non-administrative users have Write or Modify access to the directory - vulnerable to privilege escalation attack

User is affected if Claude Code version is below 2.1.75 AND the C:\ProgramData\ClaudeCode\ directory exists with a managed-settings.json file that can be written by low-privilege users.

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 2.1.75 or later
Fixed in 2.1.75
Interim mitigation

Upgrade Claude Code to version 2.1.75 or later. On shared multi-user systems, verify that no unauthorized configuration files exist in C:\ProgramData\ClaudeCode\ and consider implementing access controls on that directory.

Recommended fix High confidence

Claude Code 2.1.75

  1. Upgrade Claude Code to version 2.1.75 or later
  2. Verify the upgrade was successful by launching Claude Code
  3. Confirm that the application loads configuration from a secure, validated location

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

Fix this in Claude Code Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,696.

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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-2026-35603 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