⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Medium · CVSS 4.3

How to Fix CVE-2026-2301: Missing authorization in Post Duplicator

By Sai Kiran Pandrala. Last verified: 2026-05-25.

CVE-2026-2301 is a missing authorization in metaphorcreations Post Duplicator. The fix is to apply the vendor patch noted below.

⚡ At a glance
Severity4.3 (Medium)
Actively exploited?No public listing in CISA KEV
AffectedPost Duplicator 0 to <=3.0.8
Fixed inSee vendor advisory
Type (CWE)CWE-862 Missing Authorization

What is CVE-2026-2301?

The Post Duplicator plugin for WordPress is vulnerable to unauthorized arbitrary protected post meta insertion in all versions up to, and including, 3.0.8. This is due to the duplicate_post() function in includes/api.php using $wpdb->insert() directly to the wp_postmeta table instead of WordPress's standard add_post_meta() function, which would call is_protected_meta() to prevent lower-privileged users from setting protected meta keys (those starting with _). This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary protected post meta keys such as _wp_page_template, _wp_attached_file, and other sensitive meta keys on duplicated posts via the customMetaData JSON array parameter in the /wp-json/post-duplicator/v1/duplicate-post REST API endpoint. The CVSS base score is 4.3 (Medium). The official advisory is at https://www.wordfence.com/threat-intel/vulnerabilities/id/e5c86f72-934c-4f3b-ab2a-65df1490ca8a?source=cve.

Am I affected?

Check the version of Post Duplicator you are running and compare it against the Affected row above (Post Duplicator 0 to <=3.0.8). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:


# Linux package check
dpkg -s post-duplicator 2>/dev/null | grep -i ^Version
rpm -q post-duplicator 2>/dev/null
command -v post-duplicator >/dev/null && post-duplicator --version 2>/dev/null


# Windows (PowerShell)
Get-Package -Name "*Post Duplicator*" -ErrorAction SilentlyContinue | Select-Object Name, Version
winget list --name "Post Duplicator" 2>$null

How to fix CVE-2026-2301

Upgrade Post Duplicator to a patched build: See vendor advisory. The vendor advisory is the source of truth for the exact fixed version.

Ubuntu / Debian


sudo apt-get update
sudo apt-get install --only-upgrade post-duplicator
dpkg -s post-duplicator | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux


sudo dnf upgrade --refresh post-duplicator -y
# or for older releases:
sudo yum update post-duplicator -y
rpm -q post-duplicator

SUSE / openSUSE


sudo zypper refresh
sudo zypper update post-duplicator
rpm -q post-duplicator

Node.js / npm


# Update the affected package in your project
npm install Post Duplicator@latest
npm ls Post Duplicator
npm audit fix

PHP / Composer


composer update metaphorcreations/post-duplicator 2>/dev/null || composer update
composer show | head -20

WordPress


# Update via WP-CLI
wp plugin update --all
wp core update

Complete PowerShell remediation script (Windows)


# Fix script for CVE-2026-2301 affecting Post Duplicator
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-2301-fix-$(Get-Date -Format yyyyMMdd-HHmmss).log"
New-Item -ItemType Directory -Force (Split-Path $LogPath) | Out-Null
Start-Transcript -Path $LogPath -Append

try {
    Write-Host "[1/4] Detect installed version"
    $pkg = Get-Package -Name "*Post Duplicator*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

    Write-Host "[2/4] Backup configuration"
    $backup = "C:\Backup\post-duplicator-$(Get-Date -Format yyyyMMdd)"
    New-Item -ItemType Directory -Force $backup | Out-Null
    Get-ChildItem "C:\ProgramData\Post Duplicator" -ErrorAction SilentlyContinue |
        Copy-Item -Destination $backup -Recurse -Force -ErrorAction SilentlyContinue

    Write-Host "[3/4] Apply the upgrade to See vendor advisory"
    winget upgrade --name "Post Duplicator" --silent --accept-source-agreements --accept-package-agreements
    if ($LASTEXITCODE -ne 0) {
        # Fallback: pull latest via OS update channel
        Install-Module -Name PSWindowsUpdate -Force -SkipPublisherCheck -ErrorAction SilentlyContinue
        Import-Module PSWindowsUpdate
        Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot
    }

    Write-Host "[4/4] Verify the patched build"
    winget list --name "Post Duplicator"
    Write-Host "Patch applied. Reboot if prompted."
    exit 0
} catch {
    Write-Error "Patch failed: $_"
    exit 1
} finally {
    Stop-Transcript
}

Complete Bash remediation script (Linux)


#!/usr/bin/env bash
# Fix script for CVE-2026-2301 affecting Post Duplicator
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-2301-fix-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG") 2>&1

echo "[1/4] Detect installed version"
if command -v dpkg >/dev/null; then
    dpkg -s post-duplicator 2>/dev/null | grep -i ^Version || echo "post-duplicator not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q post-duplicator || echo "post-duplicator not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-2301-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/post-duplicator /etc/post-duplicator.d /etc/post-duplicator.conf; do
    [ -e "$d" ] && cp -a "$d" "$BACKUP/" || true
done

echo "[3/4] Apply the upgrade (target: See vendor advisory)"
if command -v apt-get >/dev/null; then
    apt-get update
    apt-get install --only-upgrade -y post-duplicator
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y post-duplicator
elif command -v yum >/dev/null; then
    yum update -y post-duplicator
elif command -v zypper >/dev/null; then
    zypper --non-interactive update post-duplicator
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s post-duplicator 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q post-duplicator
fi
echo "Done. Restart any service that loaded the old library."

If you can't patch immediately

Apply at least one of the following inline controls until you can deploy the patched build. None replace the upgrade.

Restrict exposure with nftables (Linux)


# Allow only trusted CIDR to reach the affected service ports
sudo nft add table inet filter 2>/dev/null || true
sudo nft 'add chain inet filter input { type filter hook input priority 0 ; }' 2>/dev/null || true
sudo nft 'add rule inet filter input tcp dport {80, 443} ip saddr != 10.0.0.0/8 drop'
sudo nft list ruleset

Block at the host firewall (Windows)


New-NetFirewallRule -DisplayName "Block-CVE-2026-2301" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-2301"

Disable the affected service (Linux)


sudo systemctl stop post-duplicator 2>/dev/null || true
sudo systemctl disable post-duplicator 2>/dev/null || true

If the vendor advisory lists an official workaround, prefer that wording verbatim. If no workaround is published, the only safe remediation is the patch.

How to verify the fix worked

After upgrading, confirm the installed version matches the patched build and that no old library is still loaded by a long-running process.


# Linux
dpkg -s post-duplicator 2>/dev/null | grep -i ^Version
rpm -q post-duplicator 2>/dev/null || true
# Pid map check for old library handles
sudo lsof +c0 2>/dev/null | grep -i "DEL.*lib" || true


# Windows
Get-Package -Name "*Post Duplicator*" | Select-Object Name, Version
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5

Expected: the reported version is at or above See vendor advisory. Restart the affected service (systemctl restart <service> on Linux, or restart the Windows service) so it loads the patched binary.

Frequently asked questions

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

Is CVE-2026-2301 actively exploited?

There is no public confirmation of exploitation in the wild listed in CISA KEV at the time of this writing. Patch anyway. Public exploits commonly follow disclosure within weeks.

Do I need to reboot after patching CVE-2026-2301?

For kernel and OS-level updates, yes. For most userland packages a systemctl restart <service> is enough on Linux, and restarting the Windows service or app on Windows. Any process that loaded the old library keeps using it until restarted.

What is the CVSS score for CVE-2026-2301?

4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

Where is the official advisory for CVE-2026-2301?

The vendor advisory is at https://www.wordfence.com/threat-intel/vulnerabilities/id/e5c86f72-934c-4f3b-ab2a-65df1490ca8a?source=cve. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-2301.

References

*Written by Sai Kiran Pandrala. Assembled from the official vendor advisory, NVD record, and CISA KEV listing on 2026-05-25. Always confirm against the vendor's advisory before applying changes in production.*