mysqltuner – MySQL’s maximum memory usage is dangerously high

We have a cPanel server with the following in my.cnf.

slow_query_log=1

slow_query_log_file=/var/log/mysql-slow-query.log

long_query_time=1

log_queries_not_using_indexes=1

skip-name-resolve

join_buffer_size=600K

#tmp_table_size=50M

#key_buffer_size=2147483648

#max_heap_table_size=50M

table_open_cache=2400

innodb_log_file_size=640M

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

innodb_buffer_pool_size=5G

innodb_buffer_pool_instances=5

max_allowed_packet=800M

open_files_limit=10240

innodb_file_per_table=1

max_connections=120

Database size is 7G.

Variables to adjust:
*** MySQL’s maximum memory usage is dangerously high ***
*** Add RAM before increasing MySQL buffer variables ***
join_buffer_size (> 600.0K, or always use indexes with JOINs)
tmp_table_size (> 16M)
max_heap_table_size (> 16M)
table_open_cache (> 2400)
innodb_buffer_pool_size (>= 5.9G) if possible.

          total        used        free      shared  buff/cache   available

Mem: 62G 15G 9.8G 2.2G 36G 44G
Swap: 1.0G 54M 969M

I cannot seem to get around this. Any help is appreciated