● Medium · CVSS 4.9

How to Fix CVE-2026-3523: Sql injection in Apocalypse Meow

Q: What is the CVSS score for CVE-2026-3523?

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

Q: Where is the official advisory for CVE-2026-3523?

The vendor advisory is at [https://www.wordfence.com/threat-intel/vulnerabilities/id/a1af9757-23e9-41d2-bbcd-15b0610b6538?source=cve](https://www.wordfence.com/threat-intel/vulnerabilities/id/a1af9757-23e9-41d2-bbcd-15b0610b6538?source=cve). The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-3523.

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

CVE-2026-3523 is a SQL injection in blobfolio Apocalypse Meow. The fix is to apply the vendor patch noted below.

⚡ At a glance


Severity	4.9 (Medium)
Actively exploited?	No public listing in CISA KEV
Affected	Apocalypse Meow 0 to <=22.1.0
Fixed in	See vendor advisory
Type (CWE)	CWE-89 Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')

What is CVE-2026-3523?

The Apocalypse Meow plugin for WordPress is vulnerable to SQL Injection via the 'type' parameter in all versions up to, and including, 22.1.0. This is due to a flawed logical operator in the type validation check on line 261 of ajax.php — the condition uses && (AND) instead of || (OR), causing the in_array() validation to be short-circuited and never evaluated for any non-empty type value. Combined with stripslashes_deep() being called on line 101 which removes wp_magic_quotes() protection, attacker-controlled single quotes pass through unescaped into the SQL query on line 298. This makes it possible for authenticated attackers, with Administrator-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database. The CVSS base score is 4.9 (Medium). The official advisory is at https://www.wordfence.com/threat-intel/vulnerabilities/id/a1af9757-23e9-41d2-bbcd-15b0610b6538?source=cve.

Am I affected?

Check the version of Apocalypse Meow you are running and compare it against the Affected row above (Apocalypse Meow 0 to <=22.1.0). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:


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


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

How to fix CVE-2026-3523

Upgrade Apocalypse Meow 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 apocalypse-meow
dpkg -s apocalypse-meow | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux


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

SUSE / openSUSE


sudo zypper refresh
sudo zypper update apocalypse-meow
rpm -q apocalypse-meow

PHP / Composer


composer update blobfolio/apocalypse-meow 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-2026-3523 affecting Apocalypse Meow
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-3523-fix-$(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"
    $pkg = Get-Package -Name "*Apocalypse Meow*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

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

    Write-Host "[3/4] Apply the upgrade to See vendor advisory"
    winget upgrade --name "Apocalypse Meow" --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 "Apocalypse Meow"
    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-2026-3523 affecting Apocalypse Meow
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-3523-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 apocalypse-meow 2>/dev/null | grep -i ^Version || echo "apocalypse-meow not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q apocalypse-meow || echo "apocalypse-meow not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-3523-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/apocalypse-meow /etc/apocalypse-meow.d /etc/apocalypse-meow.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 apocalypse-meow
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y apocalypse-meow
elif command -v yum >/dev/null; then
    yum update -y apocalypse-meow
elif command -v zypper >/dev/null; then
    zypper --non-interactive update apocalypse-meow
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s apocalypse-meow 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q apocalypse-meow
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-2026-3523" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-3523"

Disable the affected service (Linux)


sudo systemctl stop apocalypse-meow 2>/dev/null || true
sudo systemctl disable apocalypse-meow 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 apocalypse-meow 2>/dev/null | grep -i ^Version
rpm -q apocalypse-meow 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 "*Apocalypse Meow*" | 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:

How to Fix CVE-2026-24176: CWE-863 Incorrect Authorization in KAI Scheduler — CWE-863 Incorrect Authorization in KAI Scheduler
How to Fix CVE-2026-40962: Integer overflow in FFmpeg , Integer overflow in FFmpeg
How to Fix CVE-2026-45181: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection , Improper Neutralization of Argument Delimiters in a Command ('Argument Injection
How to Fix CVE-2026-23844: Critical Vulnerability in whisper-money , Critical Vulnerability in whisper-money
How to Fix CVE-2026-25227: Code Injection RCE in authentik , Code Injection RCE in authentik

Is CVE-2026-3523 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-2026-3523?

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-2026-3523?

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

Where is the official advisory for CVE-2026-3523?

The vendor advisory is at https://www.wordfence.com/threat-intel/vulnerabilities/id/a1af9757-23e9-41d2-bbcd-15b0610b6538?source=cve. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-3523.

References

Official vendor advisory: https://www.wordfence.com/threat-intel/vulnerabilities/id/a1af9757-23e9-41d2-bbcd-15b0610b6538?source=cve
NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3523
CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Additional reference: https://plugins.trac.wordpress.org/browser/apocalypse-meow/trunk/lib/blobfolio/wp/meow/ajax.php#L298
Additional reference: https://plugins.trac.wordpress.org/browser/apocalypse-meow/tags/22.1.0/lib/blobfolio/wp/meow/ajax.php#L298
Additional reference: https://plugins.trac.wordpress.org/browser/apocalypse-meow/trunk/lib/blobfolio/wp/meow/ajax.php#L261

*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.*