Updated xorg-x11-server packages that fix multiple security issues are now available for Red Hat Enterprise Linux 5 and 6. The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section. Description X.Org is an open source implementation of the X Window System. It provides the basic low-level functionality that full-fledged graphical user interfaces are designed upon. Multiple input sanitization flaws were found in the X.Org GLX extension. A malicious, authorized client could use these flaws to crash the X.Org server or, potentially, execute arbitrary code with root privileges. An input sanitization flaw was found in the X.Org Render extension. A malicious, authorized client could use this flaw to leak arbitrary memory from the X.Org server process, or possibly crash the X.Org server. Users of xorg-x11-server should upgrade to these updated packages, which contain backported patches to resolve these issues. All running X.Org server instances must be restarted for this update to take effect.