The fix changes the PHP equal identifier == to the identical identifier ===.
blog.wpscan.org/wordpress/security/release/2019/10/15/wordpress-524-security-release-breakdown.html
github.com/WordPress/WordPress/commit/b183fd1cca0b44a92f0264823dd9f22d2fd8b8d0
wordpress.org/news/2019/10/wordpress-5-2-4-security-release/