This release address a few small security issues, and also corrects some regressions that occurred in PHP 4.4.1. All PHP 4 users are encouraged to upgrade to this release. Some of the key changes of PHP 4.4.2 include:
* HTTP Response Splitting has been addressed in the header() function.
* An XSS problem inside the error reporting functionality has been removed.
* Apache 2 regression with sub-request handling on non-Linux systems has been fixed.
* A regression with the key() and current() functions have been fixed.
* Over 30 various bug fixes.
Further details about this release can be found in the release announcement
and the full list of changes is available in the PHP 4 ChangeLog