Updated libXfont packages that fix three security issues are now available for Red Hat Enterprise Linux 6 and 7. Red Hat Product Security has rated this update as having Important 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. The libXfont packages provide the X.Org libXfont runtime library. X.Org is an open source implementation of the X Window System. A use-after-free flaw was found in the way libXfont processed certain font files when attempting to add a new directory to the font path. A malicious, local user could exploit this issue to potentially execute arbitrary code with the privileges of the X.Org server. Multiple out-of-bounds write flaws were found in the way libXfont parsed replies received from an X.org font server. A malicious X.org server could cause an X client to crash or, possibly, execute arbitrary code with the privileges of the X.Org server. Red Hat would like to thank the X.org project for reporting these issues. Upstream acknowledges Ilja van Sprundel as the original reporter. Users of libXfont should upgrade to these updated packages, which contain a backported patch to resolve this issue. All running X.Org server instances must be restarted for the update to take effect.