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Guide How to Fix PHP2Shell (CVE-2026-109618/109619) on FASTPANEL

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How to Fix PHP2Shell (CVE-2026-109618/109619) on FASTPANEL

On 21 October 2026 PHP released emergency fixes for two critical bugs, CVE-2026-109618 and CVE-2026-109619 ("PHP2Shell"). They can let an attacker run code on your server without logging in, and attacks are already happening. This guide shows how to patch a server running FASTPANEL, step by step.

New to PHP2Shell? Read the overview first: PHP2Shell explained: what it is and how to fix it.

The fixed versions
Your PHP must be at least: 8.5.12, 8.4.27, 8.3.36 or 8.2.35. Older branches (7.4 to 8.1) need a patched build from your vendor. Update every PHP version installed, not just the one your main site uses.

Step 1: See which PHP versions you have
In FASTPANEL, open the menu (top left) and go to Applications, then search for php. Note every PHP version that is installed. Your sites can use different versions, so check each site's PHP setting too.

From the terminal, this finds every PHP binary on the server:
Code:
ls /etc/php/ /opt/ 2>/dev/null for b in $(ls /usr/bin/php[0-9]* /opt/php*/bin/php 2>/dev/null); do echo "$b $($b -r 'echo PHP_VERSION;')"; done

Step 2: Update PHP
Take a snapshot of the server first. Check for PHP package updates with apt:
Code:
apt update apt list --upgradable 2>/dev/null | grep -i php apt -y upgrade
If no PHP packages are listed as upgradable yet, the patched builds for your PHP versions may not be out yet. Check again later, and apply the temporary protection below in the meantime. FASTPANEL's Applications page also shows when an update is available for an installed component.

Step 3: Restart PHP-FPM
Code:
systemctl list-units --type=service | grep -i 'php.*fpm' systemctl restart php8.3-fpm # repeat for each service listed

Step 4: Confirm
Run the version loop from Step 1 again, and do the browser check below for at least one site per PHP version.

Check the version your websites really use
The command line can show a different PHP from the one serving websites. To be sure, create a file called
Code:
v.php
in a website's folder containing:
Code:
<?php echo PHP_VERSION;
Open
Code:
https://your-domain/v.php
, check the number, then delete the file.

Can't update yet? Temporary protection
These settings reduce the risk until a patched version is installed. They are not a full fix. Add them to the php.ini of each PHP version (or the site's PHP settings in FASTPANEL), then restart PHP:
Code:
session.upload_progress.enabled = 0 ; PHP 8.5 only: fatal_error_backtraces = 0
Don't set these with
Code:
ini_set()
or a
Code:
.user.ini
file; they must be set server-side. The PHP team also suggests
Code:
memory_limit = -1
against CVE-2026-109618, but that removes PHP's memory cap, so only use it short-term and with care.

After patching: check you weren't hit
Attacks started on 17 October, before the fix existed. Spend ten minutes on these checks:
  • PHP files created or changed since 17 October that you don't recognise, especially in upload folders:
    Code:
    find /var/www -name "*.php" -newermt 2026-10-17 -type f 2>/dev/null | head -50
  • Unknown cron jobs:
    Code:
    crontab -l
    for root and each site user.
  • Unusual CPU use (crypto miners are common):
    Code:
    ps aux --sort=-%cpu | head
If something looks wrong, change the passwords and API keys your PHP apps use, because these bugs can leak memory contents.

Questions? Ask in FASTPANEL Security & Firewall Support with your OS, FASTPANEL version and the output of your PHP version check.

Sources (checked 22 October 2026): Tenable PHP2Shell FAQ · Qualys: mitigate and patch PHP2Shell
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How to Fix PHP2Shell (CVE-2026-109618/109619) on FASTPANEL - by JAY - 10-22-2026, 03:43 PM

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