Updated libXfont packages that fix one security issue are now available for Red Hat Enterprise Linux 5 and 6. The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System base score, which gives a detailed severity rating, is available from the CVE link 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 stack-based buffer overflow flaw was found in the way the libXfont library parsed Glyph Bitmap Distribution Format fonts. A malicious, local user could exploit this issue to potentially execute arbitrary code with the privileges of the X.Org server. 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.