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Version 4.2.1

On April 27, 2015, WordPress 4.2.1 was released to the public. This is a security update for all previous WordPress versions.

Installation/Update Information

To download WordPress 4.2.1, 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:

Summary

From the announcement post, WordPress 4.2.1 fixes a critical cross-site scripting (XSS) vulnerability, which could enable commenters to compromise a site.

List of Files Revised

readme.html
wp-admin/about.php
wp-admin/includes/upgrade.php
wp-includes/version.php
wp-includes/wp-db.php
See also: other WordPress Versions.