I've found it:
What is CS and AR?*
AR = Approval rate. That is (number of posts approved) / (number of posts submitted). (Posts that are "Closed" are not considered for the posts submitted count)
CS = Curation Score = (Number of posts approved) * AR^2
Your CS determines your submission limits, and adjusts dynamically on a weekly basis. The CS algorithm means only submit if you're 100% sure your submission will be approved. There's a very heafty penalty for disapprovals.
Where can I find my CS?
It updates weekly and is published every Monday in Curie Weekly Update.