Vinagre is a VNC Client for the GNOME Desktop.
Alfredo Ortega (Core Security Technologies) reported a format string error in the vinagre_utils_show_error() function in src/vinagre-utils.c.
A remote attacker could entice a user into opening a specially crafted .vnc file or connecting to a malicious server, possibly resulting in the remote execution of arbitrary code with the privileges of the user running the application.
There is no known workaround at this time.
All Vinagre users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/vinagre-0.5.2"