diff --git a/src/wp-includes/html-api/class-wp-html-processor.php b/src/wp-includes/html-api/class-wp-html-processor.php
index a1fce26d41c04..9658a1ecdbf0b 100644
--- a/src/wp-includes/html-api/class-wp-html-processor.php
+++ b/src/wp-includes/html-api/class-wp-html-processor.php
@@ -2484,7 +2484,7 @@ private function step_in_select() {
 	 * This internal function performs the 'in select in table' insertion mode
 	 * logic for the generalized WP_HTML_Processor::step() function.
 	 *
-	 * @since 6.7.0 Stub implementation.
+	 * @since 6.7.0
 	 *
 	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
 	 *
@@ -2494,7 +2494,52 @@ private function step_in_select() {
 	 * @return bool Whether an element was found.
 	 */
 	private function step_in_select_in_table() {
-		$this->bail( "No support for parsing in the '{$this->state->insertion_mode}' state." );
+		$token_name = $this->get_token_name();
+		$token_type = $this->get_token_type();
+		$op_sigil   = '#tag' === $token_type ? ( parent::is_tag_closer() ? '-' : '+' ) : '';
+		$op         = "{$op_sigil}{$token_name}";
+
+		switch ( $op ) {
+			/*
+			 * > A start tag whose tag name is one of: "caption", "table", "tbody", "tfoot", "thead", "tr", "td", "th"
+			 */
+			case '+CAPTION':
+			case '+TABLE':
+			case '+TBODY':
+			case '+TFOOT':
+			case '+THEAD':
+			case '+TR':
+			case '+TD':
+			case '+TH':
+				// @todo Indicate a parse error once it's possible.
+				$this->state->stack_of_open_elements->pop_until( 'SELECT' );
+				$this->reset_insertion_mode();
+				return $this->step( self::REPROCESS_CURRENT_NODE );
+
+			/*
+			 * > An end tag whose tag name is one of: "caption", "table", "tbody", "tfoot", "thead", "tr", "td", "th"
+			 */
+			case '-CAPTION':
+			case '-TABLE':
+			case '-TBODY':
+			case '-TFOOT':
+			case '-THEAD':
+			case '-TR':
+			case '-TD':
+			case '-TH':
+				// @todo Indicate a parse error once it's possible.
+				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( $token_name ) ) {
+					return $this->step();
+				}
+				$this->state->stack_of_open_elements->pop_until( 'SELECT' );
+				$this->reset_insertion_mode();
+				return $this->step( self::REPROCESS_CURRENT_NODE );
+		}
+
+		/*
+		 * > Anything else
+		 */
+		return $this->step_in_select();
 	}
 
 	/**