See the blog post:
https://blog.jquery.com/2020/04/10/jquery-3-5-0-released/
and the upgrade guide:
https://jquery.com/upgrade-guide/3.5/
NOTE: Despite being a minor release, this update includes a breaking change that we had to make to fix a security issue ( CVE-2020-11022). Please follow the blog post & the upgrade guide for more details.