diff --git a/src/wp-includes/class-wp-query.php b/src/wp-includes/class-wp-query.php
index d25493dc5c4e1..ad660a665ea6d 100644
--- a/src/wp-includes/class-wp-query.php
+++ b/src/wp-includes/class-wp-query.php
@@ -1101,6 +1101,7 @@ public function parse_query( $query = '' ) {
 		if ( ! empty( $qv['post_type'] ) ) {
 			if ( is_array( $qv['post_type'] ) ) {
 				$qv['post_type'] = array_map( 'sanitize_key', $qv['post_type'] );
+				sort( $qv['post_type'] );
 			} else {
 				$qv['post_type'] = sanitize_key( $qv['post_type'] );
 			}
@@ -1109,6 +1110,7 @@ public function parse_query( $query = '' ) {
 		if ( ! empty( $qv['post_status'] ) ) {
 			if ( is_array( $qv['post_status'] ) ) {
 				$qv['post_status'] = array_map( 'sanitize_key', $qv['post_status'] );
+				sort( $qv['post_status'] );
 			} else {
 				$qv['post_status'] = preg_replace( '|[^a-z0-9_,-]|', '', $qv['post_status'] );
 			}
@@ -1181,9 +1183,12 @@ public function parse_tax_query( &$q ) {
 
 				$term = $q[ $t->query_var ];
 
-				if ( is_array( $term ) ) {
-					$term = implode( ',', $term );
+				if ( ! is_array( $term ) ) {
+					$term = explode( ',', $term );
+					$term = array_map( 'trim', $term );
 				}
+				sort( $term );
+				$term = implode( ',', $term );
 
 				if ( str_contains( $term, '+' ) ) {
 					$terms = preg_split( '/[+]+/', $term );
@@ -1219,7 +1224,8 @@ public function parse_tax_query( &$q ) {
 
 			$cat_array = preg_split( '/[,\s]+/', urldecode( $q['cat'] ) );
 			$cat_array = array_map( 'intval', $cat_array );
-			$q['cat']  = implode( ',', $cat_array );
+			sort( $cat_array );
+			$q['cat'] = implode( ',', $cat_array );
 
 			foreach ( $cat_array as $cat ) {
 				if ( $cat > 0 ) {
@@ -1261,7 +1267,8 @@ public function parse_tax_query( &$q ) {
 
 		if ( ! empty( $q['category__in'] ) ) {
 			$q['category__in'] = array_map( 'absint', array_unique( (array) $q['category__in'] ) );
-			$tax_query[]       = array(
+			sort( $q['category__in'] );
+			$tax_query[] = array(
 				'taxonomy'         => 'category',
 				'terms'            => $q['category__in'],
 				'field'            => 'term_id',
@@ -1271,6 +1278,7 @@ public function parse_tax_query( &$q ) {
 
 		if ( ! empty( $q['category__not_in'] ) ) {
 			$q['category__not_in'] = array_map( 'absint', array_unique( (array) $q['category__not_in'] ) );
+			sort( $q['category__not_in'] );
 			$tax_query[]           = array(
 				'taxonomy'         => 'category',
 				'terms'            => $q['category__not_in'],
@@ -1303,6 +1311,7 @@ public function parse_tax_query( &$q ) {
 				foreach ( (array) $tags as $tag ) {
 					$tag                 = sanitize_term_field( 'slug', $tag, 0, 'post_tag', 'db' );
 					$q['tag_slug__in'][] = $tag;
+					sort( $q['tag_slug__in'] );
 				}
 			} elseif ( preg_match( '/[+\r\n\t ]+/', $q['tag'] ) || ! empty( $q['cat'] ) ) {
 				$tags = preg_split( '/[+\r\n\t ]+/', $q['tag'] );
@@ -1313,6 +1322,7 @@ public function parse_tax_query( &$q ) {
 			} else {
 				$q['tag']            = sanitize_term_field( 'slug', $q['tag'], 0, 'post_tag', 'db' );
 				$q['tag_slug__in'][] = $q['tag'];
+				sort( $q['tag_slug__in'] );
 			}
 		}
 
@@ -1326,6 +1336,7 @@ public function parse_tax_query( &$q ) {
 
 		if ( ! empty( $q['tag__in'] ) ) {
 			$q['tag__in'] = array_map( 'absint', array_unique( (array) $q['tag__in'] ) );
+			sort( $q['tag__in'] );
 			$tax_query[]  = array(
 				'taxonomy' => 'post_tag',
 				'terms'    => $q['tag__in'],
@@ -1334,6 +1345,7 @@ public function parse_tax_query( &$q ) {
 
 		if ( ! empty( $q['tag__not_in'] ) ) {
 			$q['tag__not_in'] = array_map( 'absint', array_unique( (array) $q['tag__not_in'] ) );
+			sort( $q['tag__not_in'] );
 			$tax_query[]      = array(
 				'taxonomy' => 'post_tag',
 				'terms'    => $q['tag__not_in'],
@@ -1352,7 +1364,8 @@ public function parse_tax_query( &$q ) {
 
 		if ( ! empty( $q['tag_slug__in'] ) ) {
 			$q['tag_slug__in'] = array_map( 'sanitize_title_for_query', array_unique( (array) $q['tag_slug__in'] ) );
-			$tax_query[]       = array(
+			sort( $q['tag_slug__in'] );
+			$tax_query[] = array(
 				'taxonomy' => 'post_tag',
 				'terms'    => $q['tag_slug__in'],
 				'field'    => 'slug',
@@ -2185,8 +2198,11 @@ public function get_posts() {
 			$where          .= " AND {$wpdb->posts}.post_name = '" . $q['attachment'] . "'";
 		} elseif ( is_array( $q['post_name__in'] ) && ! empty( $q['post_name__in'] ) ) {
 			$q['post_name__in'] = array_map( 'sanitize_title_for_query', $q['post_name__in'] );
-			$post_name__in      = "'" . implode( "','", $q['post_name__in'] ) . "'";
-			$where             .= " AND {$wpdb->posts}.post_name IN ($post_name__in)";
+			// Duplicate array before sorting to allow for the orderby clause.
+			$post_name__in_for_where = $q['post_name__in'];
+			sort( $post_name__in_for_where );
+			$post_name__in = "'" . implode( "','", $post_name__in_for_where ) . "'";
+			$where        .= " AND {$wpdb->posts}.post_name IN ($post_name__in)";
 		}
 
 		// If an attachment is requested by number, let it supersede any post number.
@@ -2198,9 +2214,13 @@ public function get_posts() {
 		if ( $q['p'] ) {
 			$where .= " AND {$wpdb->posts}.ID = " . $q['p'];
 		} elseif ( $q['post__in'] ) {
-			$post__in = implode( ',', array_map( 'absint', $q['post__in'] ) );
+			$post__in_for_where = $q['post__in'];
+			// Duplicate array before sorting to allow for the orderby clause.
+			sort( $post__in_for_where );
+			$post__in = implode( ',', array_map( 'absint', $post__in_for_where ) );
 			$where   .= " AND {$wpdb->posts}.ID IN ($post__in)";
 		} elseif ( $q['post__not_in'] ) {
+			sort( $q['post__not_in'] );
 			$post__not_in = implode( ',', array_map( 'absint', $q['post__not_in'] ) );
 			$where       .= " AND {$wpdb->posts}.ID NOT IN ($post__not_in)";
 		}
@@ -2208,9 +2228,13 @@ public function get_posts() {
 		if ( is_numeric( $q['post_parent'] ) ) {
 			$where .= $wpdb->prepare( " AND {$wpdb->posts}.post_parent = %d ", $q['post_parent'] );
 		} elseif ( $q['post_parent__in'] ) {
-			$post_parent__in = implode( ',', array_map( 'absint', $q['post_parent__in'] ) );
+			// Duplicate array before sorting to allow for the orderby clause.
+			$post_parent__in_for_where = $q['post_parent__in'];
+			sort( $post_parent__in_for_where );
+			$post_parent__in = implode( ',', array_map( 'absint', $post_parent__in_for_where ) );
 			$where          .= " AND {$wpdb->posts}.post_parent IN ($post_parent__in)";
 		} elseif ( $q['post_parent__not_in'] ) {
+			sort( $q['post_parent__not_in'] );
 			$post_parent__not_in = implode( ',', array_map( 'absint', $q['post_parent__not_in'] ) );
 			$where              .= " AND {$wpdb->posts}.post_parent NOT IN ($post_parent__not_in)";
 		}
@@ -2348,9 +2372,15 @@ public function get_posts() {
 		}
 
 		if ( ! empty( $q['author__not_in'] ) ) {
+			if ( is_array( $q['author__not_in'] ) ) {
+				sort( $q['author__not_in'] );
+			}
 			$author__not_in = implode( ',', array_map( 'absint', array_unique( (array) $q['author__not_in'] ) ) );
 			$where         .= " AND {$wpdb->posts}.post_author NOT IN ($author__not_in) ";
 		} elseif ( ! empty( $q['author__in'] ) ) {
+			if ( is_array( $q['author__in'] ) ) {
+				sort( $q['author__in'] );
+			}
 			$author__in = implode( ',', array_map( 'absint', array_unique( (array) $q['author__in'] ) ) );
 			$where     .= " AND {$wpdb->posts}.post_author IN ($author__in) ";
 		}
@@ -2587,6 +2617,7 @@ public function get_posts() {
 			if ( ! is_array( $q_status ) ) {
 				$q_status = explode( ',', $q_status );
 			}
+			sort( $q_status );
 			$r_status = array();
 			$p_status = array();
 			$e_status = array();
diff --git a/tests/phpunit/tests/query/parseQuery.php b/tests/phpunit/tests/query/parseQuery.php
index bbf3f1217fb2e..94ced1ecd6e75 100644
--- a/tests/phpunit/tests/query/parseQuery.php
+++ b/tests/phpunit/tests/query/parseQuery.php
@@ -151,7 +151,7 @@ public function test_parse_query_cat_array_mixed() {
 			)
 		);
 
-		$this->assertSame( '1,-1', $q->query_vars['cat'] );
+		$this->assertSame( '-1,1', $q->query_vars['cat'] );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/rest-api/rest-posts-controller.php b/tests/phpunit/tests/rest-api/rest-posts-controller.php
index 31ed21d6782b7..fc8105afab726 100644
--- a/tests/phpunit/tests/rest-api/rest-posts-controller.php
+++ b/tests/phpunit/tests/rest-api/rest-posts-controller.php
@@ -1574,7 +1574,7 @@ public function test_get_items_not_sticky_with_exclude() {
 		$this->assertNotContains( $id2, $ids );
 		$this->assertNotContains( $id3, $ids );
 
-		$this->assertPostsWhere( " AND {posts}.ID NOT IN ($id3,$id2) AND {posts}.post_type = 'post' AND (({posts}.post_status = 'publish'))" );
+		$this->assertPostsWhere( " AND {posts}.ID NOT IN ($id2,$id3) AND {posts}.post_type = 'post' AND (({posts}.post_status = 'publish'))" );
 	}
 
 	public function test_get_items_not_sticky_with_exclude_no_sticky_posts() {