libXfont is the X.Org Xfont library, some parts are based on the FreeType code base.
Several integer overflows have been found in the PCF font parser.
A local attacker could possibly execute arbitrary code or crash the Xserver by enticing a user to load a specially crafted PCF font file.
Do not use untrusted PCF Font files.
All libXfont users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=x11-libs/libXfont-1.2.0-r1"