Silverstripe CMS needs to be installed on a web server. Content authors and website administrators use their web browser to access a web-based GUI to do their day-to-day work. Website designers and developers require access to the files on the server to update templates, website logic, and perform upgrades or maintenance.
- PHP >=7.3
- PHP extensions:
- PHP configuration:
memory_limitwith at least
- PHP extension for image manipulation: Either
- PHP extension for a database connector (e.g.
Use phpinfo() to inspect your configuration.
Silverstripe CMS tracks the official PHP release support timeline. When a PHP version reaches end-of-life, Silverstripe CMS drops support for it in the next minor release.
- MySQL >=5.6 ( built-in, commercially supported)
- PostgreSQL (third party module, community supported)
- SQL Server (third party module, community supported)
- SQLite (third party module, community supported)
Default MySQL Collation
In Silverstripe CMS Recipe 4.7 and later, new projects default to the
utf8mb4_unicode_ci collation when running
against MySQL, which offers better support for multi-byte characters such as emoji. However, this may cause issues
related to Varchar fields exceeding the maximum indexable size:
- MySQL 5.5 and lower cannot support indexes larger than 768 bytes (192 characters)
- MySQL 5.6 supports larger indexes (3072 bytes) if the
innodb_large_prefixsetting is enabled (but not by default)
- MySQL 5.7 and newer have
innodb_large_prefixenabled by default
- MariaDB ~10.1 matches MySQL 5.6's behaviour, >10.2 matches 5.7's.
You can rectify this issue by upgrading MySQL, enabling the
innodb_large_prefix setting if available, or reducing the
size of affected fields. If none of these solutions are currently suitable, you can remove the new collation
app/_config/mysite.yml to default back to the previous default collation.
Existing projects that upgrade to Recipe 4.7.0 will unintentionally adopt this configuration change. Recipe 4.7.1 and later are unaffected. See the release notes for more information.
Connection mode (sql_mode) when using MySQL server >=5.7.5
In MySQL versions >=5.7.5, the
ANSI sql_mode setting behaves differently and includes the
setting. It is generally recommended to leave this setting as-is because it results in deterministic SQL. However, for
some advanced cases, the sql_mode can be configured on the database connection via the configuration API (
MySQLDatabase::$sql_mode for more details.) This setting is only available in Silverstripe CMS 4.7 and later.
Silverstripe CMS needs to handle a variety of HTTP requests, and relies on the hosting environment to be configured securely to enforce restrictions. There are secure defaults in place for Apache, but you should be aware of the configuration regardless of your webserver setup.
The webroot of your webserver should be configured to the
public/ subfolder. Projects created prior to Silverstripe CMS
4.1 might be using the main project folder as the webroot. In this case, you are responsible for ensuring access to
system files such as configuration in
*.yml is protected from public access. We strongly recommend switching to more
secure hosting via the
public/. See 4.1.0 upgrading guide.
During runtime, Silverstripe CMS needs read access for the webserver user to your base path (including your webroot). It also needs write access for the webserver user to the following locations:
public/assets/: Used by the CMS and other logic to store uploads
TEMP_PATH: Temporary file storage used for the default filesystem-based cache adapters in Manifests, Object Caching and Partial Template Caching. See Environment Management.
If you aren't explicitly packaging your Silverstripe CMS project during your deployment process, additional write access may be required to generate supporting files on the fly. This is not recommended, because it can lead to extended execution times as well as cause inconsistencies between multiple server environments when manifest and cache storage isn't shared between servers.
Silverstripe CMS allows CMS authors to upload files into the
public/assets/ folder, which should be served by your
webserver. No PHP execution should be allowed in this folder. This is configured for Apache by default
public/assets/.htaccess. The file is generated dynamically during the
Additionally, access is whitelisted by file extension through a dynamically generated whitelist based on
(see File Security). This whitelist uses the same defaults
configured through file upload through Silverstripe CMS, so is considered a second line of defence.
Files can be kept in draft stage, and access restricted to certain user groups. These files are stored in a
.protected/ folder (defaulting to
Requests to files in this folder should be denied by your webserver.
Requests to files in the
.protected/ folder are routed to PHP by default when using Apache,
public/assets/.htaccess. If you are using another webserver, please follow our guides to ensure a secure
setup. See Developer Guides: File Security for details.
For additional security, we recommend moving the
.protected/ folder out of
public/assets/. This removes the
possibility of a misconfigured webserver accidentally exposing these files under URL paths, and forces read access via
This can be configured via .env variable, relative to the
The resulting folder structure will look as follows:
.protected/ <hash>/my-protected-file.txt public/ index.php assets/ my-public-file.txt vendor/ app/
Don't forget to include this additional folder in any syncing and backup processes!
Building, Packaging and Deployment
It is common to build a Silverstripe CMS application into a package on one environment (e.g. a CI server), and then deploy the package to a (separate) webserver environment(s). This approach relies on all auto-generated files required by Silverstripe CMS to be included in the package, or generated on the fly on each webserver environment.
The easiest way to ensure this is to commit auto generated files to source control. If those changes are considered too noisy, here's some pointers for auto-generated files to trigger and include in a deployment package:
public/_resources/: Frontend assets copied from the (inaccessible)
vendor/folder via silverstripe/vendor-plugin. See Templates: Requirements.
public/_graphql/: Schema and type definitions required by CMS and any GraphQL API endpoint. Generated through silverstripe/graphql v4. Triggered by
dev/build, or a GraphQL Schema Build.
- Various recipes create default files in
composer updatevia silverstripe/recipe-plugin.
Web Worker Concurrency
It's generally a good idea to run multiple workers to serve multiple HTTP requests to Silverstripe CMS concurrently. The exact number depends on your website needs. The CMS attempts to request multiple views concurrently. It also routes protected and draft files through Silverstripe CMS. This can increase your concurrency requirements, e.g. when authors batch upload and view dozens of draft files in the CMS.
When allowing upload of large files through the CMS (through PHP settings), these files might be used as protected and draft files. Files in this state get served by Silverstripe CMS rather than your webserver. Since the framework uses PHP streams, this allows serving of files larger than your PHP memory limit. Please be aware that streaming operations don't count towards PHP's max_execution_time, which can risk exhaustion of web worker pools for long-running downloads.
Silverstripe CMS expects URL paths to be rewritten to
public/index.php. For Apache, this is preconfigured
.htaccess files, and expects using the
mod_rewrite module. By default, these files are located
Silverstripe CMS can add HTTP headers to responses it handles directly. These headers are often sensitive, for example
preventing HTTP caching for responses displaying data based on user sessions, or when serving protected assets. You need
to ensure those headers are kept in place in your webserver. For example, Apache allows this
Header setifempty (see docs).
See Developer Guide: Performance
and Developer Guides: File Security for more details.
Silverstripe CMS relies on the
Host header to construct URLs such as "reset password" links, so you'll need to ensure that
the systems hosting it only allow valid values for this header.
See Developer Guide: Security - Request hostname forgery
CDNs and other Reverse Proxies
If your Silverstripe CMS site is hosted behind multiple HTTP layers, you're in charge of controlling which forwarded headers are considered valid, and which IPs can set them. See Developer Guide: Security - Request hostname forgery .
Silverstripe CMS is a modular system, with modules installed and updated via the
composer PHP dependency manager. These
are usually stored in
vendor/, outside of the
public/ webroot. Since many modules rely on serving frontend assets
such as CSS files or images, these are mapped over to the
public/_resources/ folder automatically. If the filesystem
supports it, this is achieved through symlinks. Depending on your hosting and deployment mechanisms, you may need to
configure the plugin to copy files instead.
See silverstripe/vendor-plugin for details.
Silverstripe CMS relies on various caches to achieve performant responses. By default, those caches are stored in a temporary filesystem folder, and are not shared between multiple server instances. Alternative cache backends such as Redis can be configured.
While cache objects can expire, when using filesystem caching the files are not actively pruned. For long-lived server instances, this can become a capacity issue over time - see workaround.
The default installation
includes silverstripe/errorpage, which generates
static error pages that bypass PHP execution when those pages are published in the CMS. Once published, the static files
are located in
public/assets/error-500.html. The default
public/.htaccess file is
configured to have Apache serve those pages based on their HTTP status code.
Other webservers (Nginx, IIS, Lighttpd)
Serving through webservers other than Apache requires more manual configuration, since the defaults configured
.htaccess don't apply. Please apply the considerations above to your webserver to ensure a secure hosting
environment. In particular, configure protected assets correctly to avoid exposing draft or protected files uploaded
through the CMS.
There are various community supported installation instructions for different environments. Nginx is a popular choice, see Nginx webserver configuration.
Silverstripe CMS is known to work with Microsoft IIS, and generates
web.config files by default
see Microsoft IIS and SQL Server configuration)
Additionally, there are community supported guides for installing Silverstripe CMS on various environments:
- Hosting via Bitnami: In the cloud or as a locally hosted virtual machine
- Vagrant/Virtualbox with CentOS
- macOS with Homebrew
- macOS with MAMP
- Windows with WAMP
- Vagrant with silverstripe-australia/vagrant-environment
- Vagrant with BetterBrief/vagrant-skeleton
Silverstripe CMS uses SwiftMailer to send email messages. New installations setup with silverstripe/installer are configured to use a
sendmail found in
/usr/sbin/sendmail or another location specified via configuration. Alternatively email can be configured to use SMTP or other mail transports instead of sendmail.
You must ensure emails are being sent from your production environment. You can do this by testing that the Lost password form available at
/Security/lostpassword sends an email to your inbox, or with the following code snippet that can be run via a
$email = new SilverStripe\Control\Email\Email('firstname.lastname@example.org', 'email@example.com', 'My test subject', 'My email body text'); $email->send();
Using the code snippet above also tests that the ability to set the "from" address is working correctly.
See the email section for futher details, including how to set the administrator "from" email address, change the
sendmail binary location and how to use SMTP or other mail transports instead of sendmail.
PHP Requirements for older Silverstripe CMS releases
Silverstripe CMS's PHP support has changed over time and if you are looking to upgrade PHP on your Silverstripe CMS site, this table may be of use:
|Silverstripe CMS Version||PHP Version||More information|
|3.0 - 3.5||5.3 - 5.6|
|3.6||5.3 - 7.1|
|3.7||5.3 - 7.4||changelog|
|4.0 - 4.4||5.6+|
|4.5 - 4.9||7.1+||blog post|
CMS browser requirements
Silverstripe CMS supports the following web browsers:
- Google Chrome
- Internet Explorer 11
- Microsoft Edge
- Mozilla Firefox
We aim to provide satisfactory experiences in Apple Safari. Silverstripe CMS works well across Windows, Linux, and Mac operating systems.
End user requirements