Do socialists believe in objective morality?

When I read certain texts from Marx, it appears that Marx viewed the emergence of socialism as a dialectical historical process rather than moral progress. Whereas a lot of socialists Ive talk to seem to portray the capitalists as evil people and the struggle for socialism as a kind of a moral battle. Additionally, a lot of socialist and related discourse seems to portray morality, religion as social constructs that just serve the interest of the ruling classes. So do socialists view socialism as an alternative social construct that serves the interests of the oppressed and working classes or as a objectively good moral framework to replace the capitalist morals and values?