diff -u b/core/modules/filter/filter.module b/core/modules/filter/filter.module
--- b/core/modules/filter/filter.module
+++ b/core/modules/filter/filter.module
@@ -453,8 +453,7 @@
  * Provides filtering of input into accepted HTML.
  */
 function _filter_html($text, $filter) {
-  $forbidden_tags = preg_split('/\s+|<|>/', $filter->settings['forbidden_html'], -1, PREG_SPLIT_NO_EMPTY);
-  $text = Html::stripTagContent($text, $forbidden_tags);
+  $text = Html::stripTagContent($text);
   $allowed_tags = preg_split('/\s+|<|>/', $filter->settings['allowed_html'], -1, PREG_SPLIT_NO_EMPTY);
   $text = Xss::filter($text, $allowed_tags);
 
reverted:
--- b/core/modules/filter/src/Plugin/Filter/FilterHtml.php
+++ a/core/modules/filter/src/Plugin/Filter/FilterHtml.php
@@ -21,7 +21,6 @@
  *   type = Drupal\filter\Plugin\FilterInterface::TYPE_HTML_RESTRICTOR,
  *   settings = {
  *     "allowed_html" = "<a> <em> <strong> <cite> <blockquote> <code> <ul> <ol> <li> <dl> <dt> <dd> <h4> <h5> <h6>",
- *     "forbidden_html" = "<style> <script>",
  *     "filter_html_help" = TRUE,
  *     "filter_html_nofollow" = FALSE
  *   },