On the PHP.net site they've announced the release of version 5.4.15 & 5.3.25 (fully released after some propagation issues with the mirror servers).

The PHP development team announces the immediate availability of PHP 5.4.15 and PHP 5.3.25. These releases fix about 10 bugs aswell as upgrading the bundled libmagic library. All users of PHP are encouraged to upgrade to PHP 5.4.15. [...] The list of changes are recorded in the ChangeLog.

Changes include updates to debug_backtrace for a segfault issue, a change to the dns_get_record function for negative length values and a fix for a fd leak on Solaris. You can download this latest release from the downloads section (source) or the Windows QA site (binaries).