diff --git a/src/wp-includes/kses.php b/src/wp-includes/kses.php
index 6a579b8d91..2c0e075ff4 100644
--- a/src/wp-includes/kses.php
+++ b/src/wp-includes/kses.php
@@ -230,6 +230,7 @@ if ( ! CUSTOM_TAGS ) {
 			'border'   => true,
 			'height'   => true,
 			'hspace'   => true,
+			'loading'  => true,
 			'longdesc' => true,
 			'vspace'   => true,
 			'src'      => true,
diff --git a/tests/phpunit/tests/kses.php b/tests/phpunit/tests/kses.php
index 69870a7033..2c5a6c6706 100644
--- a/tests/phpunit/tests/kses.php
+++ b/tests/phpunit/tests/kses.php
@@ -765,6 +765,11 @@ EOF;
 				'src="mypic.jpg"',
 				'src="mypic.jpg"',
 			),
+			array(
+				'img',
+				'loading="lazy"',
+				'loading="lazy"',
+			),
 			array(
 				'img',
 				'onerror=alert(1)',
@@ -1352,4 +1357,26 @@ EOF;
 			),
 		);
 	}
+
+	/**
+	 * Test filtering a standard img tag.
+	 *
+	 * @ticket 50731
+	 */
+	function test_wp_kses_img_tag_standard_attributes() {
+		$html = array(
+			'<img',
+			'loading="lazy"',
+			'src="https://example.com/img.jpg"',
+			'width="1000"',
+			'height="1000"',
+			'alt=""',
+			'class="wp-image-1000"',
+			'/>',
+		);
+
+		$html = implode( ' ', $html );
+
+		$this->assertSame( $html, wp_kses_post( $html ) );
+	}
 }