Multiple security issues have been found in the Xen virtualisation solution, which may result in denial of service or information disclosure.
The oldstable distribution (wheezy) will be updated in a separate DSA.
For the stable distribution (jessie), these problems have been fixed in version 4.4.1-9+deb8u4.
For the unstable distribution (sid), these problems will be fixed soon.
We recommend that you upgrade your xen packages.
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/