KDE is a feature-rich graphical desktop environment for Linux and Unix-like Operating Systems. kjs is the javascript interpreter used in Konqueror and other parts of KDE.
Maksim Orlovich discovered an incorrect bounds check in kjs when handling URIs.
By enticing a user to load a specially crafted webpage containing malicious javascript, an attacker could execute arbitrary code with the rights of the user running kjs.
There is no known workaround at this time.
All kdelibs users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose kde-base/kdelibs-3.4.3-r1