diff --git a/src/wp-includes/class-wp-theme-json.php b/src/wp-includes/class-wp-theme-json.php
index e48bdfa1541dd..c1bc6209f306d 100644
--- a/src/wp-includes/class-wp-theme-json.php
+++ b/src/wp-includes/class-wp-theme-json.php
@@ -395,6 +395,7 @@ class WP_Theme_JSON {
 	 * @since 6.6.0 Added support for 'dimensions.aspectRatios', 'dimensions.defaultAspectRatios',
 	 *              'typography.defaultFontSizes', and 'spacing.defaultSpacingSizes'.
 	 * @since 6.9.0 Added support for `border.radiusSizes`.
+	 * @since 7.0.0 Added type markers to the schema for boolean values.
 	 * @var array
 	 */
 	const VALID_SETTINGS = array(
@@ -442,8 +443,8 @@ class WP_Theme_JSON {
 			'allowCustomContentAndWideSize' => null,
 		),
 		'lightbox'                      => array(
-			'enabled'      => null,
-			'allowEditing' => null,
+			'enabled'      => true,
+			'allowEditing' => true,
 		),
 		'position'                      => array(
 			'fixed'  => null,
@@ -1246,6 +1247,7 @@ protected static function get_blocks_metadata() {
 	 * It is recursive and modifies the input in-place.
 	 *
 	 * @since 5.8.0
+	 * @since 7.0.0 Added type validation for boolean values.
 	 *
 	 * @param array $tree   Input to process.
 	 * @param array $schema Schema to adhere to.
@@ -1263,6 +1265,17 @@ protected static function remove_keys_not_in_schema( $tree, $schema ) {
 				continue;
 			}
 
+			// Validate type if schema specifies a boolean marker.
+			if ( is_bool( $schema[ $key ] ) ) {
+				// Schema expects a boolean value - validate the input matches.
+				if ( ! is_bool( $value ) ) {
+					unset( $tree[ $key ] );
+					continue;
+				}
+				// Type matches, keep the value and continue to next key.
+				continue;
+			}
+
 			if ( is_array( $schema[ $key ] ) ) {
 				if ( ! is_array( $value ) ) {
 					unset( $tree[ $key ] );
@@ -3673,6 +3686,35 @@ protected static function remove_insecure_inner_block_styles( $blocks ) {
 		return $sanitized;
 	}
 
+	/**
+	 * Preserves valid typed settings from input to output based on type markers in schema.
+	 *
+	 * Recursively iterates through the schema and validates/preserves settings
+	 * that have type markers (e.g., boolean) in VALID_SETTINGS.
+	 *
+	 * @since 7.0.0
+	 *
+	 * @param array             $input  Input settings to process.
+	 * @param array             $output Output settings array (passed by reference).
+	 * @param array             $schema Schema to validate against (typically VALID_SETTINGS).
+	 * @param array<string|int> $path   Current path in the schema (for recursive calls).
+	 */
+	private static function preserve_valid_typed_settings( $input, &$output, $schema, $path = array() ) {
+		foreach ( $schema as $key => $schema_value ) {
+			$current_path = array_merge( $path, array( $key ) );
+
+			// Validate boolean type markers.
+			if ( is_bool( $schema_value ) ) {
+				$value = _wp_array_get( $input, $current_path, null );
+				if ( is_bool( $value ) ) {
+					_wp_array_set( $output, $current_path, $value ); // Preserve boolean value.
+				}
+			} elseif ( is_array( $schema_value ) ) {
+				self::preserve_valid_typed_settings( $input, $output, $schema_value, $current_path ); // Recurse into nested structure.
+			}
+		}
+	}
+
 	/**
 	 * Processes a setting node and returns the same node
 	 * without the insecure settings.
@@ -3732,6 +3774,9 @@ protected static function remove_insecure_settings( $input ) {
 		// Ensure indirect properties not included in any `PRESETS_METADATA` value are allowed.
 		static::remove_indirect_properties( $input, $output );
 
+		// Preserve all valid settings that have type markers in VALID_SETTINGS.
+		self::preserve_valid_typed_settings( $input, $output, static::VALID_SETTINGS );
+
 		return $output;
 	}
 
diff --git a/tests/phpunit/tests/theme/wpThemeJson.php b/tests/phpunit/tests/theme/wpThemeJson.php
index 2bf0e7d84f266..aeb89f323e77a 100644
--- a/tests/phpunit/tests/theme/wpThemeJson.php
+++ b/tests/phpunit/tests/theme/wpThemeJson.php
@@ -5999,8 +5999,8 @@ public function test_internal_syntax_is_converted_to_css_variables() {
 	 * @ticket 58588
 	 * @ticket 60613
 	 *
-	 * @covers WP_Theme_JSON_Gutenberg::resolve_variables
-	 * @covers WP_Theme_JSON_Gutenberg::convert_variables_to_value
+	 * @covers WP_Theme_JSON::resolve_variables
+	 * @covers WP_Theme_JSON::convert_variables_to_value
 	 */
 	public function test_resolve_variables() {
 		$primary_color   = '#9DFF20';
@@ -6623,4 +6623,132 @@ public function test_merge_incoming_data_unique_slugs_always_preserved() {
 
 		$this->assertEqualSetsWithIndex( $expected, $actual );
 	}
+
+	/**
+	 * @covers WP_Theme_JSON::sanitize
+	 * @covers WP_Theme_JSON::remove_keys_not_in_schema
+	 *
+	 * @ticket 64280
+	 */
+	public function test_sanitize_preserves_boolean_values_when_schema_expects_boolean() {
+		$theme_json = new WP_Theme_JSON(
+			array(
+				'version'  => WP_Theme_JSON::LATEST_SCHEMA,
+				'settings' => array(
+					'lightbox' => array(
+						'enabled'      => true,
+						'allowEditing' => false,
+					),
+				),
+			)
+		);
+
+		$settings = $theme_json->get_settings();
+		$this->assertTrue( $settings['lightbox']['enabled'], 'Enabled should be true' );
+		$this->assertFalse( $settings['lightbox']['allowEditing'], 'Allow editing should be false' );
+	}
+
+	/**
+	 * @covers WP_Theme_JSON::sanitize
+	 * @covers WP_Theme_JSON::remove_keys_not_in_schema
+	 *
+	 * @ticket 64280
+	 */
+	public function test_sanitize_removes_non_boolean_values_when_schema_expects_boolean() {
+		$theme_json = new WP_Theme_JSON(
+			array(
+				'version'  => WP_Theme_JSON::LATEST_SCHEMA,
+				'settings' => array(
+					'lightbox' => array(
+						'enabled'      => 'not-a-boolean',
+						'allowEditing' => 123,
+					),
+				),
+			)
+		);
+
+		$settings = $theme_json->get_settings();
+		$this->assertArrayNotHasKey( 'enabled', $settings['lightbox'] ?? array(), 'Enabled should be removed' );
+		$this->assertArrayNotHasKey( 'allowEditing', $settings['lightbox'] ?? array(), 'Allow editing should be removed' );
+	}
+
+	/**
+	 * @covers WP_Theme_JSON::sanitize
+	 * @covers WP_Theme_JSON::remove_keys_not_in_schema
+	 *
+	 * @ticket 64280
+	 */
+	public function test_sanitize_preserves_boolean_values_in_block_settings() {
+		$theme_json = new WP_Theme_JSON(
+			array(
+				'version'  => WP_Theme_JSON::LATEST_SCHEMA,
+				'settings' => array(
+					'blocks' => array(
+						'core/image' => array(
+							'lightbox' => array(
+								'enabled'      => true,
+								'allowEditing' => false,
+							),
+						),
+					),
+				),
+			)
+		);
+
+		$settings = $theme_json->get_settings();
+		$this->assertTrue( $settings['blocks']['core/image']['lightbox']['enabled'], 'Enabled should be true' );
+		$this->assertFalse( $settings['blocks']['core/image']['lightbox']['allowEditing'], 'Allow editing should be false' );
+	}
+
+	/**
+	 * @covers WP_Theme_JSON::sanitize
+	 * @covers WP_Theme_JSON::remove_keys_not_in_schema
+	 *
+	 * @ticket 64280
+	 */
+	public function test_sanitize_removes_non_boolean_values_in_block_settings() {
+		$theme_json = new WP_Theme_JSON(
+			array(
+				'version'  => WP_Theme_JSON::LATEST_SCHEMA,
+				'settings' => array(
+					'blocks' => array(
+						'core/image' => array(
+							'lightbox' => array(
+								'enabled'      => 'string-value',
+								'allowEditing' => array( 'not', 'a', 'boolean' ),
+							),
+						),
+					),
+				),
+			)
+		);
+
+		$settings = $theme_json->get_settings();
+		$lightbox = $settings['blocks']['core/image']['lightbox'] ?? array();
+		$this->assertArrayNotHasKey( 'enabled', $lightbox, 'Enabled should be removed' );
+		$this->assertArrayNotHasKey( 'allowEditing', $lightbox, 'Allow editing should be removed' );
+	}
+
+	/**
+	 * @covers WP_Theme_JSON::sanitize
+	 * @covers WP_Theme_JSON::remove_keys_not_in_schema
+	 *
+	 * @ticket 64280
+	 */
+	public function test_sanitize_preserves_null_schema_behavior() {
+		// Test that settings with null in schema (no type validation) still accept any type.
+		$theme_json = new WP_Theme_JSON(
+			array(
+				'version'  => WP_Theme_JSON::LATEST_SCHEMA,
+				'settings' => array(
+					'appearanceTools' => 'string-value', // null in schema, should accept any type.
+					'custom'          => array( 'nested' => 'value' ), // null in schema, should accept any type.
+				),
+			)
+		);
+
+		$settings = $theme_json->get_settings();
+		$this->assertSame( 'string-value', $settings['appearanceTools'], 'Appearance tools should be string value' );
+		$this->assertSame( array( 'nested' => 'value' ), $settings['custom'], 'Custom should be array value' );
+	}
 }