Backports unserialize options introduced in PHP 7.0 to older PHP versions.

v1.0.4 2019-07-14 23:16 UTC


Backports unserialize options introduced in PHP 7.0 to older PHP versions. This was originally designed as a Proof of Concept for Symfony Issue #21090.

You can use this package in projects that rely on PHP versions older than PHP 7.0. In case you are using PHP 7.0+ the original unserialize() will be used instead.

From the documentation:


Do not pass untrusted user input to unserialize() regardless of the options value of allowed_classes. Unserialization can result in code being loaded and executed due to object instantiation and autoloading, and a malicious user may be able to exploit this. Use a safe, standard data interchange format such as JSON (via json_decode() and json_encode()) if you need to pass serialized data to the user.


  • PHP 5.3+


You can install this package via composer:

composer require brumann/polyfill-unserialize "^1.0"

Known Issues

There is a mismatch in behavior when allowed_classes in $options is not of the correct type (array or boolean). PHP 7.0 will not issue a warning that an invalid type was provided. This library will trigger a warning, similar to the one PHP 7.1+ will raise and then continue, assuming false to make sure no classes are deserialized by accident.


You can run the test suite using PHPUnit. It is intentionally not bundled as dev dependency to make sure this package has the lowest restrictions on the implementing system as possible.

Please read the PHPUnit Manual for information how to install it on your system.

You can run the test suite as follows:

phpunit -c phpunit.xml.dist tests/


This package is considered feature complete. As such I will likely not update it unless there are security issues.

Should you find any bugs or have questions, feel free to submit an Issue or a Pull Request on GitHub.