The PHP development team is proud to announce the immediate release of PHP 5.3.1. This is a maintenance release in the 5.3 series, which includes a large number of bug fixes.

Security Enhancements and Fixes in PHP 5.3.1:

• Added "max_file_uploads" INI directive, which can be set to limit the number of file uploads per-request to 20 by default, to prevent possible DOS via temporary file exhaustion.
• Added missing sanity checks around exif processing.
• Fixed a safe_mode bypass in tempnam().
• Fixed a open_basedir bypass in posix_mkfifo().
• Fixed bug #50063 (safe_mode_include_dir fails).
• Fixed bug #44683 (popen crashes when an invalid mode is passed).

Key Bug Fixes in PHP 5.3.1 include:

• Fixed crash in com_print_typeinfo when an invalid typelib is given.
• Fixed crash in SQLiteDatabase::ArrayQuery() and SQLiteDatabase::SingleQuery() when calling using Reflection.
• Fixed crash when instantiating PDORow and PDOStatement through Reflection.
• Fixed bug #49910 (no support for ././@LongLink for long filenames in phar tar support).
• Fixed bug #49908 (throwing exception in __autoload crashes when interface is not defined).
• Around 100 other bug fixes

For users upgrading from PHP 5.2 there is a migration guide available here, detailing the changes between those releases and PHP 5.3.

For a full list of changes in PHP 5.3.1, see the ChangeLog.