PHP2Shell in Synology: is it affected and how to fix it

How to check the PHP version Synology uses

Run the command for your setup. A version at or above 8.2.35, 8.3.36, 8.4.27 or 8.5.12 in its branch is fixed; older branches are fixed only by a vendor build that says so.

ls /var/packages/ | grep -i php

Or open Package Center → Installed and look at the PHP 8.x package version.

The command-line php can differ from the PHP that serves the site. To be sure, check the web SAPI (a temporary phpinfo() page behind authentication, or the panel's PHP settings) and remove it afterwards. Our version checker compares a version number for you.

🔎 Got a version number? Paste it into the PHP2Shell checker →

How to fix PHP2Shell in Synology

If Web Station hosts sites reachable from the internet, remove the port forwarding or put them behind a VPN until Synology ships fixed PHP packages.
Keep Package Center auto-updates on and recheck the PHP package version.
Until the vendor ships fixed PHP, the PHP-based interface should not be reachable from untrusted networks: restrict it to a management network, an IP allowlist or a VPN.
Install the vendor update as soon as it appears and re-check the version.

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If you cannot patch yet

Set session.upload_progress.enabled = 0 where applications cannot override it (php.ini, php_admin_value in the FPM pool or Apache config), and restart PHP.
On PHP 8.5, set fatal_error_backtraces = 0.
PHP's interim advice also covers memory_limit and a low post_max_size; follow the remediation page exactly, because these settings only reduce some paths.
Restrict access (VPN, IP allowlist) or take the service offline if it runs PHP 8.1 or older with no vendor backport. WAF rules help but are not a fix.

FAQ

Is Synology affected by PHP2Shell?

Likely affected: no vendor fix or statement found. DSM's built-in PHP is command-line only and is not exposed through the management interface. The optional Web Station PHP packages (8.2.30, 8.3.30, 8.4.19) were not fixed, and we found no Synology statement about them.

Does updating Synology itself fix CVE-2026-109618 and CVE-2026-109619?

Only if the update contains fixed PHP. PHP2Shell is a flaw in the PHP interpreter, so what matters is the PHP that Synology runs on. Check the version after updating.

Which PHP versions fix PHP2Shell?

PHP 8.2.35, 8.3.36, 8.4.27 and 8.5.12, released 21 October 2026. PHP 8.1 and older get no release from the PHP project; only vendor builds with a backport (or a self-built source patch for 7.4, 8.0 and 8.1) fix them.

What if Synology has no fix yet?

Keep its PHP-based web interface off the internet (VPN or IP allowlist), apply PHP's interim settings such as disabling session upload progress, and install the vendor update as soon as it ships. Interim settings reduce risk but are not a fix.

← All products that bundle PHP

Sources

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Unofficial summary of public sources. This site is not affiliated with the vendor or the PHP project and hosts no exploit code.