--- /dev/null
+<?php
+
+namespace Drupal\block_test\Plugin\Block;
+
+/**
+ * Provides a block to test XSS in title.
+ *
+ * @Block(
+ * id = "test_xss_title",
+ * admin_label = "<script>alert('XSS subject');</script>"
+ * )
+ */
+class TestXSSTitleBlock extends TestCacheBlock {
+}