The Xen Project has published Xen Security Advisories 317, 319, 327, and 328 (XSA-317, XSA-319, XSA-327, and XSA-328, respectively). These XSAs do not affect the security of Qubes OS, and no user action is necessary.
This is a companion discussion topic for the original entry at https://www.qubes-os.org/news/2020/07/07/xsa-317-319-327-328-qubes-not-affected/