diff --git a/Platform/user/configm/config-server/netconfig/ipconfig/ipconfig.c b/Platform/user/configm/config-server/netconfig/ipconfig/ipconfig.c
index b717884a8..5a8ee84be 100644
--- a/Platform/user/configm/config-server/netconfig/ipconfig/ipconfig.c
+++ b/Platform/user/configm/config-server/netconfig/ipconfig/ipconfig.c
@@ -170,7 +170,8 @@ ret_code ip_config_json_parse(pointer input, uint *conf_type, ip_config_t *confi
     else if(config_buff->family == AF_INET6)
     {    
         config_buff->ipv6.prefixlen = strtoul(ip_config->prefixlen, 0, 0);
-        if(config_buff->ipv6.prefixlen > IPV6_MAX_PREFIXLEN)
+        if(config_buff->ipv6.prefixlen > IPV6_MAX_PREFIXLEN 
+           || config_buff->ipv6.prefixlen < 0)
         {
             ret = RET_NETMASKERR;
             goto exit;