Heap-based buffer overflow in the progressive PNG Image loader (decoders/pngloader.cpp) in KHTML in KDE 4.0.x up to 4.0.3 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted image.

KDE kmail before 5.5.2 and messagelib before 5.5.2, as distributed in KDE Applications before 17.04.2, do not ensure that a plugin's sign/encrypt action occurs during use of the Send Later feature, which allows remote attackers to obtain sensitive information by sniffing the network.

startkdeinit in KDE 3.5.5 through 3.5.9, when installed setuid root, allows local users to cause a denial of service and possibly execute arbitrary code via "user-influenceable input" (probably command-line arguments) that cause startkdeinit to send SIGUSR1 signals to other processes.

Screen savers in KDE beta 3 allows local users to overwrite arbitrary files via a symlink attack on the .kss.pid file.