Multisite wordpress and subdomain URL collisions
You could just prevent slugs matching existing directories. There are two filters for that. Example, not tested: add_filter( ‘wp_unique_post_slug_is_bad_hierarchical_slug’, ‘prevent_directory_slugs’, 10, 2 ); add_filter( ‘wp_unique_post_slug_is_bad_flat_slug’, ‘prevent_directory_slugs’, 10, 2 ); function prevent_directory_slugs( $bool, $slug ) { return is_dir( ABSPATH . “https://wordpress.stackexchange.com/” . $slug ); }