WordPress 5.1.15 Security Release

Security updates included in this release

• Media: Refactor search by filename within the admin,
• REST API: Lockdown post parameter of the terms endpoint,
• Customize: Escape blogname option in underscores templates,
• Query: Validate relation in WP_Date_Query,
• Posts, Post types: Apply KSES to post-by-email content,
• General: Validate host on “Are you sure?” screen,
• Posts, Post types: Remove emails from post-by-email logs,
• Pings/trackbacks: Apply KSES to all trackbacks,
• Mail: Reset PHPMailer properties between use,
• Widgets: Escape RSS error messages for display.