PHP 5.2.13 released fixing 3 security bugs

* Improved LCG entropy. (Rasmus, Samy Kamkar)
* Fixed safe_mode validation inside tempnam() when the directory path
does not end with a /). (Martin Jansen)
* Fixed a possible open_basedir/safe_mode bypass in the session
extension identified by Grzegorz Stachowiak. (Ilia)

For users of the 5.2 branch of PHP, it is recommended to update to
5.2.13. This version also includes 43 other, non-security related bug

For users of the 5.1 branch, 5.1.6 is the latest patched version.