In kdeconnect-kde (aka KDE Connect) before 20.08.2, an attacker on the local network could send crafted packets that trigger use of large amounts of CPU, memory, or network connection slots, aka a Denial of Service attack.
In KDE Ark before 20.08.1, a crafted TAR archive with symlinks can install files outside the extraction directory, as demonstrated by a write operation to a user's home directory.
A remote user can create a specially crafted M3U file, media playlist file that when loaded by the target user, will trigger a memory leak, whereby Amarok 2.8.0 continue to waste resources over time, eventually allows attackers to cause a denial of service.
fishProtocol::establishConnection in fish/fish.cpp in KDE kio-extras through 20.04.0 makes a cacheAuthentication call even if the user had not set the keepPassword option. This may lead to unintended KWallet storage of a password.
An issue was discovered in KDE KMail before 19.12.3. By using the proprietary (non-RFC6068) "mailto?attach=..." parameter, a website (or other source of mailto links) can make KMail attach local files to a composed email message without showing a warning to the user, as demonstrated by an attach=.bash_history value.
messagepartthemes/default/defaultrenderer.cpp in messagelib in KDE Applications before 18.12.0 does not properly restrict the handling of an http-equiv="REFRESH" value.
The %{password(...)} macro in pastemacroexpander.cpp in the KDE Paste Applet before 4.10.5 in kdeplasma-addons does not properly generate passwords, which allows context-dependent attackers to bypass authentication via a brute-force attack.