At the moment of writing this answer, there's no evidence of search engines (specially Google crawler) paying attention to ARIA attributes for HTML. ARIA attributes are not designed for SEO purposes, but for making HTML documents (or web applications) more accessible.
In fact, ARIA attributes associate a name (semantic) to an object; they are designed to assign semantical meaning to objects where the default HTML elements can't, and this information will be used in specific devices.
Search engines extract another type of information, mainly textual content inserted between HTML tags, such headings (
h6), paragraphs (
p), etc., and images through the src attribute.
However, if the accessibility improves a lot the user experiencie of the whole site, then it's possible that the website ranking improves. Is it good for the user? Then it's good for the rankings. So, answering again to your question, ARIA is not a direct ranking factor for SEO, and it's a probable indirect factor that could improve a position of a website in the SERPs.