On April 21, 2015, WordPress 3.9.4 was released to the public. This is a security update for all previous WordPress versions.
To download WordPress 3.9.4, update automatically from the Dashboard > Updates menu in your site’s admin area or visit https://wordpress.org/download/release-archive/.
For step-by-step instructions on installing and updating WordPress:
If you are new to WordPress, we recommend that you begin with the following:
- New To WordPress – Where to Start
- First Steps With WordPress or Upgrading WordPress Extended
- WordPress Lessons
From the announcement post:
- A serious critical cross-site scripting vulnerability, which could enable anonymous users to compromise a site.
- Files with invalid or unsafe names could be upload.
- Some plugins are vulnerable to an SQL injection attack.
- A very limited cross-site scripting vulnerability could be used as part of a social engineering attack.
- Four hardening changes, including better validation of post titles within the Dashboard.
List of Files Revised