There's a note over on the main PHP site, that the release of the latest version in the PHP 5.1.x series has been posted - PHP 5.1.2.

The PHP development team is proud to announce the release of PHP 5.1.2. This release combines small feature enhancements with a fair number of bug fixes and addresses three security issues. All PHP 5 users are encouraged to upgrade to this release.

Further details about this release can be found in the release announcement and the full list of changes is available in the PHP 5 ChangeLog.

Some of the larger changes in this new version include: "HTTP Response Splitting has been addressed in ext/session and in the header() function", "Upgraded OCI8 extension", and "Over 85 various bug fixes".

So, what are you waiting for? Get over and upgrade now!