WordPress released there new version, which is 5.4.1. There have some optimization, below have change log:-

Security updates #Security updates

Six security issues affect WordPress versions 5.4 and earlier; version 5.4.1 fixes them, so you’ll want to upgrade. If you haven’t yet updated to 5.4, there are also updated versions of 5.3 and earlier that fix the security issues.

• Props to Muaz Bin Abdus Sattar and Jannes who both independently reported an issue where password reset tokens were not properly invalidated
• Props to ka1n4t for finding an issue where certain private posts can be viewed unauthenticated
• Props to Evan Ricafort for discovering an XSS issue in the Customizer
• Props to Ben Bidner from the WordPress Security Team who discovered an XSS issue in the search block
• Props to Nick Daugherty from WPVIP.com / WordPress Security Team who discovered an XSS issue in wp-object-cache
• Props to Ronnie Goodrich (Kahoots) and Jason Medeiros who independently reported an XSS issue in file uploads.
• Additionally, an authenticated XSS issue in the block editor was discovered by Nguyen the Duc in WordPress 5.4 RC1 and RC2. It was fixed in 5.4 RC5. We wanted to be sure to give credit and thank them for all of their work in making WordPress more secure.

Maintenance updates #Maintenance updates

WordPress 5.4.1 also fixes some regressions introduced in version 5.4:

• #49838 – Accessibility: Fix the headings hierarchy on the Freedoms page
• #49798 – Customize: Give the WordPress logo a white background for dark mode browsers
• #49853 – Mail: Make the check for empty post title in wp-mail.php more resilient
• #49753 – Media: Remove display: none; from the (visually hidden) <input type="file"> button used in Plupload to select files for uploading. Fixes selecting files in Edge <= 44 and iOS Safari
• #49772 – Privacy: Support additional elements (table, ol, ul) in privacy policy guide new styling
• #49802 – Privacy: Make the deprecated wp_get_user_request_data() function available on front end
• #49645 – REST API: Fix revisions controller get_item permission check
• #49648 – REST API: Fix _fields filtering of registered rest fields
• #49824 – Site Health: Instantiation prevents use of some hooks by plugins
• #49759 – Taxonomy: Un-deprecate category_link and tag_link filters

Copyright: https://wordpress.org/support/wordpress-version/version-5-4-1/