diff --git a/source/dnode/mnode/impl/src/mndUser.c b/source/dnode/mnode/impl/src/mndUser.c
index 90d16a0a81..7a34e0f6a5 100644
--- a/source/dnode/mnode/impl/src/mndUser.c
+++ b/source/dnode/mnode/impl/src/mndUser.c
@@ -801,7 +801,8 @@ static int32_t mndProcessAlterUserReq(SRpcMsg *pReq) {
     goto _OVER;
   }
 
-  if (TSDB_ALTER_USER_PASSWD == alterReq.alterType && alterReq.pass[0] == 0) {
+  if (TSDB_ALTER_USER_PASSWD == alterReq.alterType && 
+      (alterReq.pass[0] == 0 || strlen(alterReq.pass) > TSDB_PASSWORD_LEN)) {
     terrno = TSDB_CODE_MND_INVALID_PASS_FORMAT;
     goto _OVER;
   }