Are there risks in sharing a paper after submission and before reviews? After submitting a paper for publication to a computer science conference,  authors are excited about their work and want to share it with friends, colleagues. Are there any risks in sharing the paper while waiting for reviews that might jeopardize its publication?

In Computer Science, conference submissions are usually subject to a double-blind review process.
I work in CS and know of no issues with distributing work to a small group of people. I know a number of researchers (myself included) who share their work with colleagues before and after submission. Sometimes it's to gather feedback, sometimes because a friend is curious about your work or working on something similar. It's generally understood that the research will not be distributed further without the authors' permission.