The Version 3.4.2 addressed some security issues and fixed 20 bugs.
The vulnerabilities included potential privilege escalation and a bug that affects multisite installs with untrusted users.
Some Fixes were:
- Fix some issues with older browsers in the administration area.
- Fix an issue where a theme may not preview correctly, or its screenshot may not be displayed.
- Improve plugin compatibility with the visual editor.
- Address pagination problems with some category permalink structures.
- Avoid errors with both oEmbed providers and trackbacks.
- Prevent improperly sized header images from being uploaded.
Upgrade to latest version – Go to your Dashboard > Updates > click the ‘update’ button.
You can read the full announcement post on WordPress.org.
Have you upgraded your site? Please let us know in the comments below.