Security Enhancements and Fixes in PHP 4.4.9:

Updated PCRE to version 7.7.

Fixed overflow in memnstr().

Fixed crash in imageloadfont when an invalid font is given.

Fixed open_basedir handling issue in the curl extension.

Fixed mbstring.func_overload set in .htaccess becomes global.

更多详细查看

http://www.php.net/ChangeLog-4.php#4.4.9