On September 6, 2012, WordPress 3.4.2 was released to the public. This is a maintenance and security update. [codex.wordpress.org ]
Following bugs were fixed:
. Fixes some issues in the admin area where some older browsers (IE7, in particular) may slow down, lag, or freeze. . Fixes an issue where a theme may not preview correctly, or its screenshot may not be displayed. . Fixes the use of multiple trackback URLs in a post. . Prevents improperly sized images from being uploaded as headers from the customizer. . Ensures proper error messages can be shown to PHP4 installs. (WordPress requires PHP 5.2.4 or later.) . Fixes handling of oEmbed providers that only return XML responses. . Addresses pagination problems with some category permalink structures. . Adds more fields to be returned from the XML-RPC wp.getPost method. . Avoids errors when updating automatically from very old versions of WordPress (pre-3.0). . Fixes problems with the visual editor when working with captions.
Also a few security issues and contains some security hardening were fixed:
Fix unfiltered HTML capabilities in multisite. . Fix possible privilege escalation in the Atom Publishing Protocol endpoint. . Allow operations on network plugins only through the network admin. . Hardening: Simplify error messages when uploads fail. . Hardening: Validate a parameter passed to wp_get_object_terms().