diff --git a/NEWS b/NEWS
index 82d364f4288..1a05e49a06a 100644
--- a/NEWS
+++ b/NEWS
@@ -35,6 +35,10 @@ PHP                                                                        NEWS
   . Fixed build regression on systems without C++17 compilers. (Calvin Buckley,
     Peter Kokot)
 
+- MySQLnd:
+  . Fix bug GH-14255 (mysqli_fetch_assoc reports error from
+    nested query). (Kamil Tekiela)
+
 - Opcache:
   . Fixed bug GH-14109 (Fix accidental persisting of internal class constant in
     shm). (ilutov)
diff --git a/ext/mysqli/mysqli.c b/ext/mysqli/mysqli.c
index f98ab2fc15f..470918c1d96 100644
--- a/ext/mysqli/mysqli.c
+++ b/ext/mysqli/mysqli.c
@@ -731,7 +731,7 @@ void php_mysqli_fetch_into_hash_aux(zval *return_value, MYSQL_RES * result, zend
 	/* TODO: We don't have access to the connection object at this point, so we use low-level
 	 * mysqlnd APIs to access the error information. We should try to pass through the connection
 	 * object instead. */
-	if (MyG(report_mode) & MYSQLI_REPORT_ERROR) {
+	if (MyG(report_mode) & MYSQLI_REPORT_ERROR && result->conn) {
 		MYSQLND_CONN_DATA *conn = result->conn;
 		unsigned error_no = conn->m->get_error_no(conn);
 		if (error_no) {
diff --git a/ext/mysqli/tests/gh14255.phpt b/ext/mysqli/tests/gh14255.phpt
new file mode 100644
index 00000000000..375eda0c5b5
--- /dev/null
+++ b/ext/mysqli/tests/gh14255.phpt
@@ -0,0 +1,31 @@
+--TEST--
+Bug GH-14255 (mysqli_fetch_assoc reports error from nested query)
+--EXTENSIONS--
+mysqli
+--SKIPIF--
+<?php
+require_once 'skipifconnectfailure.inc';
+?>
+--FILE--
+<?php
+
+require_once 'connect.inc';
+
+mysqli_report(MYSQLI_REPORT_STRICT|MYSQLI_REPORT_ERROR);
+
+$mysqli = my_mysqli_connect($host, $user, $passwd, $db, $port, $socket);
+
+$ca = $mysqli->query('SELECT 1 ');
+$c = $ca->fetch_assoc();
+try {
+    $mysqli->query('SELECT non_existent_column');
+} catch (Exception $e) {
+    echo "Caught exception"."\n";
+}
+$c = $ca->fetch_assoc();
+
+print "done!";
+?>
+--EXPECTF--
+Caught exception
+done!
diff --git a/ext/mysqlnd/mysqlnd_result.c b/ext/mysqlnd/mysqlnd_result.c
index 08faed6d058..ad63147861e 100644
--- a/ext/mysqlnd/mysqlnd_result.c
+++ b/ext/mysqlnd/mysqlnd_result.c
@@ -970,6 +970,13 @@ MYSQLND_METHOD(mysqlnd_res, fetch_into)(MYSQLND_RES * result, const unsigned int
 	bool fetched_anything;
 	zval *row_data;
 
+	// We clean the error here because in unbuffered mode we could receive a new error
+	// and therefore consumers of this method are checking for errors
+	MYSQLND_CONN_DATA *conn = result->conn;
+	if (conn) {
+		SET_EMPTY_ERROR(conn->error_info);
+	}
+
 	DBG_ENTER("mysqlnd_res::fetch_into");
 	if (FAIL == result->m.fetch_row(result, &row_data, flags, &fetched_anything)) {
 		RETVAL_FALSE;