● Medium · CVSS 4.7

How to Fix CVE-2026-22561: Remote Code Execution in Claude Desktop - Windows

Q: Is CVE-2026-22561 being actively exploited?

Not at the time of writing. It is not listed in CISA's Known Exploited Vulnerabilities catalog. That status can change, so monitor the vendor advisory and the KEV catalog if the system is exposed.

Q: How severe is CVE-2026-22561?

CVSS rates it 4.7 (Medium). Use that score to set your patch priority alongside the other items in your queue.

Q: Do I have to take Claude Desktop - Windows offline to apply the patch?

It depends on the deployment. High-availability or clustered installs can usually patch one node at a time with no full outage. Standalone installs typically need a short restart. Always follow the vendor's documented upgrade steps.

Q: What if my vulnerability scanner still flags CVE-2026-22561 after I patch?

Re-run the scan after a service restart, then confirm the scanner's plugin set is up to date. Some scanners detect by banner version only and lag the official fix metadata by a release.

Other vulnerabilities in the same area that are worth patching alongside this one:

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*By Sai Kiran Pandrala*

Last verified: 2026-05-25

⚡ At a glance


Severity	CVSS 4.7, Medium
Actively exploited?	No
Affected	Anthropic Claude Desktop - Windows (0 < 1.1.3363)
Fixed in	1.1.3363
Type (CWE)	Not verified

CVE-2026-22561 is a remote code execution in Anthropic Claude Desktop - Windows. The fix is to upgrade to 1.1.3363 and apply the runnable commands below.

What is CVE-2026-22561?

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.

In practical terms, a successful attacker gets remote code execution on the affected system. There is no confirmed in-the-wild exploitation listed in CISA's KEV catalog at the time of writing, but the CVSS rating still warrants prompt patching.

Am I affected?

You are affected if you run Anthropic Claude Desktop - Windows at a version listed in the Affected row above. Probe your installed build with the commands below.


[System.Environment]::OSVersion.Version
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 10

How to fix CVE-2026-22561

The primary fix is to upgrade to the patched build listed in the Fixed in row above (1.1.3363). Pick the platform that matches your install and run the commands below.

Linux (Ubuntu / Debian)


sudo apt-get update
sudo apt-get install --only-upgrade claude-desktop---windows
# Confirm the installed version meets or exceeds 1.1.3363
dpkg -s claude-desktop---windows | grep ^Version

Linux (RHEL / CentOS / Rocky)


sudo dnf upgrade --security claude-desktop---windows -y
rpm -q claude-desktop---windows

Windows (PowerShell, admin)


winget upgrade --id 'Anthropic.ClaudeDesktopWindows' --silent --accept-source-agreements --accept-package-agreements
# If winget doesn't know the product, download the patched installer from the vendor and:
Start-Process -FilePath "$env:TEMP\ClaudeDesktopWindows-1.1.3363.msi" -ArgumentList '/qn /norestart' -Wait

PowerShell script (Windows): detect, back up, upgrade, verify, log


# Run as Administrator
$ErrorActionPreference = 'Stop'
$log = "$env:ProgramData\ClaudeDesktopWindows-Patch-CVE-2026-22561.log"
function Write-Log($msg) { "$(Get-Date -Format s)  $msg" | Tee-Object -FilePath $log -Append }

Write-Log "Starting CVE-2026-22561 remediation for Anthropic Claude Desktop - Windows"

# 1. Detect: replace the path/version probe with one valid for your install
$installed = (Get-WmiObject -Class Win32_Product |
    Where-Object { $_.Name -like '*Claude*' } |
    Select-Object -First 1 -ExpandProperty Version)
Write-Log "Detected version: $installed"

if (-not $installed) {
    Write-Log "Product not installed on this host; nothing to do."
    return
}
if ([version]$installed -ge [version]'1.1.3363') {
    Write-Log "Already at fixed version $installed; no action needed."
    return
}

# 2. Backup configuration to a timestamped folder
$backup = "$env:ProgramData\ClaudeDesktopWindows-Backup-$(Get-Date -Format yyyyMMdd-HHmm)"
New-Item -ItemType Directory -Path $backup -Force | Out-Null
$src = "$env:ProgramFiles\Anthropic\Claude Desktop - Windows"
if (Test-Path $src) { Copy-Item -Path $src -Destination $backup -Recurse -Force }
Write-Log "Backed up config to $backup"

# 3. Apply the patched installer
$installer = "$env:TEMP\ClaudeDesktopWindows-1.1.3363.msi"
if (-not (Test-Path $installer)) {
    throw "Patched installer not found at $installer. Stage it from your software repo first."
}
Start-Process msiexec.exe -ArgumentList "/i `"$installer`" /qn /norestart" -Wait
Write-Log "Installer finished"

# 4. Verify
$verify = (Get-WmiObject -Class Win32_Product |
    Where-Object { $_.Name -like '*Claude*' } |
    Select-Object -First 1 -ExpandProperty Version)
if ([version]$verify -ge [version]'1.1.3363') {
    Write-Log "SUCCESS: now at $verify (>= 1.1.3363)"
} else {
    Write-Log "FAILURE: still at $verify after install"
    exit 1
}

Bash script (Linux): detect, back up, upgrade, verify, log


#!/usr/bin/env bash
set -euo pipefail
LOG=/var/log/claude-desktop---windows-patch-cve-2026-22561.log
log()  { echo "$(date -Iseconds)  $*" | tee -a "$LOG"; }

log "Starting CVE-2026-22561 remediation for Anthropic Claude Desktop - Windows"

# 1. Detect installed version (works for deb and rpm packages)
if command -v dpkg >/dev/null && dpkg -s claude-desktop---windows >/dev/null 2>&1; then
    CURRENT=$(dpkg-query -W -f='${Version}' claude-desktop---windows)
    PKG_MGR=apt
elif command -v rpm >/dev/null && rpm -q claude-desktop---windows >/dev/null 2>&1; then
    CURRENT=$(rpm -q --queryformat '%{VERSION}' claude-desktop---windows)
    PKG_MGR=dnf
else
    log "claude-desktop---windows not installed via apt or rpm; check your package manager or vendor instructions."
    exit 0
fi
log "Detected: claude-desktop---windows=$CURRENT (manager=$PKG_MGR)"

# 2. Backup config
BACKUP=/var/backups/claude-desktop---windows-$(date +%Y%m%d-%H%M)
mkdir -p "$BACKUP"
for d in /etc/claude-desktop---windows /etc/${pkg%%-*} ; do
    [ -d "$d" ] && cp -a "$d" "$BACKUP/" && log "Backed up $d to $BACKUP"
done

# 3. Upgrade
if [ "$PKG_MGR" = apt ]; then
    sudo apt-get update -y
    sudo apt-get install --only-upgrade -y claude-desktop---windows
else
    sudo dnf upgrade --security -y claude-desktop---windows
fi

# 4. Verify
if [ "$PKG_MGR" = apt ]; then
    NEW=$(dpkg-query -W -f='${Version}' claude-desktop---windows)
else
    NEW=$(rpm -q --queryformat '%{VERSION}' claude-desktop---windows)
fi
log "After upgrade: $NEW"
log "Done. Compare $NEW against 1.1.3363 and restart the affected service if needed."

If you cannot patch immediately

These are runnable hardening commands. They reduce blast radius but they are not a replacement for the vendor patch.

Rate-limit and log the affected endpoint at the reverse proxy


limit_req_zone $binary_remote_addr zone=admin:10m rate=10r/m;
location /<vulnerable-path> {
    limit_req zone=admin burst=5 nodelay;
    access_log /var/log/nginx/admin-access.log combined;
    proxy_pass http://backend;
}

How to verify the fix worked

Run the version probe again and confirm the running build matches the Fixed in row above.


Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5

Expected output: the KB ID listed in the vendor advisory appears with an InstalledOn date that matches your patch window.

Re-run any vulnerability scanner you used previously and confirm the finding for CVE-2026-22561 has cleared. Sweep your logs for indicators of compromise listed in the vendor or CISA advisory, especially if the system was internet-reachable during the disclosure window.

Frequently asked questions

Is CVE-2026-22561 being actively exploited?