Installing ezpublish 5.4.2 as specified on the release notes does not update ezpublis-kernel to 5.4.2 version, staying in 5.4.1.
The problem is with the kernel being dependent of friendsofsymfony/http-cache-bundle 1.2, and the packages listed for update on the release notes do not include this one.

Only by running a normal composer update (and this is not the command referred in 5.4.2 release notes):

php -d memory_limit=-1 composer.phar update --no-dev --prefer-dist

I managed to install everything properly.