Evolution is the mail client of the GNOME desktop environment.
Ulf Harnhammar from Secunia Research has discovered a format string error in the write_html() function in the file calendar/gui/e-cal-component-memo-preview.c.
A remote attacker could entice a user to open a specially crafted shared memo, possibly resulting in the execution of arbitrary code with the privileges of the user running Evolution.
There is no known workaround at this time.
All Evolution users should upgrade to the latest version:
# emerge --sync # emerge --ask --oneshot --verbose ">=mail-client/evolution-2.8.3-r2"