Security Release: WordPress 5.3.4

WordPress 5.2.4 is now available! This security release fixes 6 security issues.

WordPress versions 5.2.3 and earlier are affected by these bugs, which are fixed in version 5.2.4. Updated versions of WordPress 5.1 and earlier are also available for any users who have not yet updated to 5.2.

Security Updates

• Props to Evan Ricafort for finding an issue where stored XSS (cross-site scripting) could be added via the Customizer.
• Props to J.D. Grimes who found and disclosed a method of viewing unauthenticated posts.
• Props to Weston Ruter for finding a way to create a stored XSS to inject Javascript into style tags.
• Props to David Newman for highlighting a method to poison the cache of JSON GET requests via the Vary: Origin header.
• Props to Eugene Kolodenker who found a server-side request forgery in the way that URLs are validated.
• Props to Ben Bidner of the WordPress Security Team who discovered issues related to referrer validation in the admin.

Thank you to all of the reporters for privately disclosing the vulnerabilities, which gave us time to fix them before WordPress sites could be attacked.

WordPress 5.2.4 is a short-cycle security release. The next major release will be version 5.3.

For more info, browse the full list of changes below or on Trac or check out the Version 5.2.4 documentation page.

In addition to the security researchers mentioned above, thank you to everyone who contributed to WordPress 5.2.4:

Aaron D. Campbell, darthhexx, David Binovec, Jonathan Desrosiers, Ian Dunn, Jeff Paul, Nick Daugherty, Konstantin Obenland, Peter Wilson, Sergey Biryukov, Stanimir Stoyanov, Garth Mortensen, vortfu, Weston Ruter, Jake Spurlock, and Alex Concha.