Multiple vulnerabilities have been discovered in the Xen hypervisor, which could result in denial of service, guest-to-host privilege escalation or information leaks.
For the stable distribution (buster), these problems have been fixed in version 4.11.4+24-gddaaccbbab-1~deb10u1.
Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/