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