diff --git a/wp-includes/kses.php b/wp-includes/kses.php
index 20790d1c44..3da5bf2624 100644
--- a/wp-includes/kses.php
+++ b/wp-includes/kses.php
@@ -1076,6 +1076,7 @@ function wp_kses_attr( $element, $attr, $allowed_html, $allowed_protocols ) {
  * Determines whether an attribute is allowed.
  *
  * @since 4.2.3
+ * @since 5.0.0 Add support for `data-*` wildcard attributes.
  *
  * @param string $name         The attribute name. Passed by reference. Returns empty string when not allowed.
  * @param string $value        The attribute value. Passed by reference. Returns a filtered value.
@@ -1090,8 +1091,26 @@ function wp_kses_attr_check( &$name, &$value, &$whole, $vless, $element, $allowe
 
 	$name_low = strtolower( $name );
 	if ( ! isset( $allowed_attr[ $name_low ] ) || '' == $allowed_attr[ $name_low ] ) {
-		$name = $value = $whole = '';
-		return false;
+		/*
+		 * Allow `data-*` attributes.
+		 *
+		 * When specifying `$allowed_html`, the attribute name should be set as
+		 * `data-*` (not to be mixed with the HTML 4.0 `data` attribute, see
+		 * https://www.w3.org/TR/html40/struct/objects.html#adef-data).
+		 *
+		 * Note: the attribute name should only contain `A-Za-z0-9_-` chars,
+		 * double hyphens `--` are not accepted by WordPress.
+		 */
+		if ( strpos( $name_low, 'data-' ) === 0 && ! empty( $allowed_attr['data-*'] ) && preg_match( '/^data(?:-[a-z0-9_]+)+$/', $name_low, $match ) ) {
+			/*
+			 * Add the whole attribute name to the allowed attributes and set any restrictions
+			 * for the `data-*` attribute values for the current element.
+			 */
+			$allowed_attr[ $match[0] ] = $allowed_attr['data-*'];
+		} else {
+			$name = $value = $whole = '';
+			return false;
+		}
 	}
 
 	if ( 'style' == $name_low ) {
@@ -2091,6 +2110,7 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
  * Helper function to add global attributes to a tag in the allowed html list.
  *
  * @since 3.5.0
+ * @since 5.0.0 Add support for `data-*` wildcard attributes.
  * @access private
  * @ignore
  *
@@ -2099,11 +2119,12 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
  */
 function _wp_add_global_attributes( $value ) {
 	$global_attributes = array(
-		'class' => true,
-		'id'    => true,
-		'style' => true,
-		'title' => true,
-		'role'  => true,
+		'class'  => true,
+		'id'     => true,
+		'style'  => true,
+		'title'  => true,
+		'role'   => true,
+		'data-*' => true,
 	);
 
 	if ( true === $value ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 2b02a833c7..6f385b30fa 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.1-alpha-43980';
+$wp_version = '5.1-alpha-43981';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.