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ClaudeApplication · Anthropic

CVE-2026-22561

HIGH · 7.8 CVSS v3.1 Published 2026-03-31
Fix available
A fix is available. Upgrade to 1.1.3363 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
Uncontrolled search path elements in Anthropic Claude for Windows installer (Claude Setup.exe) versions prior to 1.1.3363 allow local privilege escalation via DLL search-order hijacking. The installer loads DLLs (e.g., profapi.dll) from its own directory after UAC elevation, enabling arbitrary code execution if a malicious DLL is planted alongside the installer.

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

The Anthropic Claude for Windows installer (Claude Setup.exe) versions prior to 1.1.3363 suffers from a DLL search-order hijacking vulnerability. After UAC elevation, the installer loads DLLs (such as profapi.dll) from its own directory instead of secure system paths, allowing a locally-placed malicious DLL to be executed with elevated privileges.

MitigationUpgrade Claude for Windows to version 1.1.3363 or later to remediate the uncontrolled search path vulnerability. Alternatively, ensure no untrusted files are placed alongside the installer executable.

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
ClaudeApplication
Affected:< 1.1.3363

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
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/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 installed Claude for Windows version
    Locate the Claude installation directory (typically C:\Program Files\Claude or C:\Program Files (x86)\Claude) and check the file version of the executable (e.g., Claude.exe or claude.exe). Right-click the file, select Properties, and view the Details tab for Product Version.
    Affected if Product version is less than 1.1.3363
  2. Check for Claude installer on system
    Search for Claude Setup.exe on the system using File Explorer search or command: dir /s /b C:\*Claude*Setup.exe
    Affected if Claude Setup.exe is found on the system (especially in user-accessible directories)
  3. Verify installer location permissions
    If Claude Setup.exe is found, right-click its containing folder, select Properties, then Security tab, and check if standard users have Write or Modify permissions to that directory.
    Affected if Installer resides in a directory writable by non-admin users (e.g., Downloads, Desktop, temp folders)
  4. Check recent Claude installation history
    Review Windows Event Viewer under Windows Logs > Application for MSI installer events related to 'Claude' or 'Anthropic' to identify when and from what path Claude was installed.
    Affected if Installation occurred from an untrusted or writable directory path

A system is affected if Claude for Windows version is below 1.1.3363, or if the Claude Setup.exe installer exists in a user-writable directory where a local attacker could have placed a malicious DLL.

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 1.1.3363 or later
Fixed in 1.1.3363
Interim mitigation

Upgrade Claude for Windows to version 1.1.3363 or later to remediate the uncontrolled search path vulnerability. Alternatively, ensure no untrusted files are placed alongside the installer executable.

Recommended fix Moderate confidence

1.1.3363 or later

  1. Obtain the fixed Claude for Windows installer (version 1.1.3363 or later) from the official Anthropic source (trust.anthropic.com or anthropic.com)
  2. Verify the digital signature and integrity of the downloaded installer before execution
  3. Run the updated installer to install or reinstall Claude with the fixed version
  4. For organizations, ensure the vulnerable installer versions are removed or replaced in software distribution systems

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

Fix this in Claude Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $890
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,424.

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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-2026-22561 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