WordPress 4.0.1 is now available, and is a critical security release for all previous versions of WordPress.
We strongly encourage you to update your sites immediately.
Sites that support automatic background updates will be updated to WordPress 4.0.1 soon, if not already. BUT, we have been seeings issue with the automatic upgrades this round, so please check your sites. If you spot any issues, please contact us for assistance.
If you are still running WordPress 3.9.2, 3.8.4, or 3.7.4, you will be updated to 3.9.3, 3.8.5, or 3.7.5 to keep everything secure. If you are running older legacy versions of WordPress, please upgrade to 4.0.1 immediately.
WordPress versions 3.9.2 and earlier are affected by a critical cross-site scripting vulnerability, which could enable anonymous users to compromise a site. This issue does not affect version 4.0, but version 4.0.1 does address these eight security issues:
- Three cross-site scripting issues that a contributor or author could use to compromise a site.
- A cross-site request forgery that could be used to trick a user into changing their password.
- An issue that could lead to a denial of service when passwords are checked.
- Additional protections for server-side request forgery attacks when WordPress makes HTTP requests.
- An extremely unlikely hash collision could allow a user’s account to be compromised, that also required that they haven’t logged in since 2008.
- WordPress now invalidates the links in a password reset email if the user remembers their password, logs in, and changes their email address.
Version 4.0.1 also fixes 23 bugs with 4.0, and also two hardening changes, including better validation of EXIF data we are extracting from uploaded photos.
As always, we highly recommend that you keep your WordPress installation, WordPress themes and WordPress plugins up to date to ensure that you’re running the most secure and feature rich version of WordPress.
If you need assistance with upgrading, please schedule your WordPress upgrade today via our WordPress Upgrade Service.
Anyone who is already subscribed to one of our upgrade packages has already been upgraded to WordPress 4.0.1. If you’d like to ensure that your site is always up to date, please check out our WordPress Maintenance Packages.