It was reported [1] that Konqueror in KDE 4.4.0 through to and including 4.6.1 is vulnerable to a partially universal XSS in error pages. When Konqueror cannot fetch a requested URL, it renders an error page that contains the given URL. If the URL were to contain JavaScript or HTML code, the code is also rendered which could allow for a user to be tricked into visiting a malicious web site or to provide credentials to an untrusted party. Patches are available for the 4.4, 4.5, and 4.6 branches, linked to from the upstream security advisory. [1] http://www.kde.org/info/security/advisory-20110411-1.txt
This affects Red Hat Enterprise Linux 6 and Fedora. It does not affect Red Hat Enterprise Linux 5 and earlier.
Nth Dimension advisory: http://www.nth-dimension.org.uk/pub/NDSA20110321.txt.asc Link to upstream master branch commit: https://projects.kde.org/projects/kde/kdelibs/repository/revisions/aaa8c42 IDs of the commits in other upstream branches are listed in the upstream advisory, as already pointed out in comment #0.
This issue has been addressed in following products: Red Hat Enterprise Linux 6 Via RHSA-2011:0464 https://rhn.redhat.com/errata/RHSA-2011-0464.html