WordPress Release: 3.9.23

TL;DR

WordPress 3.9.23 Maintenance Release

This maintenance release addresses two specific issues: a file deletion problem during upgrades and removes unnecessary MediaElement.js files. The update improves the reliability of WordPress upgrades by ensuring files can be properly removed or emptied when needed, and reduces potential security risks by removing obsolete media library files.

Highlight of the Release

• Improved file handling during WordPress upgrades
• Fallback mechanism to empty files when deletion fails
• Removal of unnecessary and obsolete MediaElement.js files

Migration Guide

No specific migration steps are required for this update. This is a maintenance release that can be applied through the standard WordPress update process.

If you've made custom modifications that reference the removed MediaElement.js files, you may need to update your code to use the current MediaElement.js files included with WordPress.

Upgrade Recommendations

This update is recommended for all WordPress 3.9 installations as it improves the reliability of future upgrades and removes unnecessary files that could potentially pose security risks.

The update can be applied through the standard WordPress update process:

1. Back up your website before updating
2. Navigate to Dashboard > Updates
3. Click "Update Now"

Alternatively, you can download the update from the WordPress.org download page and perform a manual update.

Bug Fixes

File Deletion During Upgrades

Fixed an issue where WordPress upgrades could fail when the system was unable to delete old files due to permission restrictions. Now, if a file cannot be deleted, WordPress will attempt to empty its contents instead, allowing the upgrade process to continue successfully.

Fixes #42963

New Features

Enhanced File Handling During Upgrades

WordPress now attempts to empty files when deletion fails during the upgrade process. This provides a fallback mechanism to ensure that outdated files don't remain with their original content when file permissions prevent complete removal.

Security Updates

Removal of Obsolete Media Files

Removed unnecessary and obsolete MediaElement.js files from the installation. While not explicitly labeled as a security fix, removing outdated library files is a good security practice as it reduces the potential attack surface by eliminating code that is no longer maintained or needed.

Fixes #42720

Performance Improvements

Reduced Installation Footprint

By removing unnecessary MediaElement.js files, the overall installation size has been slightly reduced, which can contribute to marginally faster loading times and less disk space usage.

Impact Summary

WordPress 3.9.23 is a targeted maintenance release that addresses specific issues related to the upgrade process and removes unnecessary files. The impact is primarily positive for site administrators, making WordPress upgrades more reliable, especially in environments with strict file permissions.

The changes in this release are focused on improving the robustness of the WordPress core rather than adding new features. By implementing a fallback mechanism for file deletion during upgrades and removing obsolete files, this release enhances the stability and security posture of WordPress 3.9 installations.

While this is a minor update in terms of visible changes, it represents WordPress's ongoing commitment to maintaining older branches with important fixes that improve reliability and security.