WordPress runs out of memory

[lvps]

Certified WordPress moment:

... wordpress-cli[6085]: crond: USER www-data pid 353791 cmd wp cron event run --path="/var/www/html" --due-now
... wordpress-cli[6085]: PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 1052672 bytes) in /var/www/html/wp-includes/class-wpdb.php on line 2321
... wordpress-cli[6085]: Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 1052672 bytes) in /var/www/html/wp-includes/class-wpdb.php on line 2321
... boulangerie.openstack.polito wordpress-cli[6085]: Error: Si è verificato un errore critico sul tuo sito web.Scopri di più riguardo la risoluzione dei problemi in WordPress. Si è verificato un errore critico sul tuo sito web.

This one, too:

... wordpress-cli[6085]: PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/wp-includes/class-wpdb.php on line 2320
... wordpress-cli[6085]: Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 20480 bytes) in /var/www/html/wp-includes/class-wpdb.php on line 2320
... wordpress-cli[6085]: PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 32768 bytes) in phar:///usr/local/bin/wp/vendor/wp-cli/php-cli-tools/lib/cli/Colors.php on line 1
... wordpress-cli[6085]: Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 32768 bytes) in phar:///usr/local/bin/wp/vendor/wp-cli/php-cli-tools/lib/cli/Colors.php on line 1

Why is it happening? How to fix it? Are there more errors?