Doomsday is a modern gaming engine for popular ID games like Doom, Heretic and Hexen.
Luigi Auriemma discovered that Doomsday incorrectly implements formatted printing.
A remote attacker could exploit these vulnerabilities to execute arbitrary code with the rights of the user running the Doomsday server or client by sending specially crafted strings.
There is no known workaround at this time.
All Doomsday users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=games-fps/doomsday-1.9.0_beta4"