plasma-workspace before 5.1.95 allows remote attackers to obtain passwords via a Trojan horse Look and Feel package.
KDE KMail does not encrypt attachments in emails when "automatic encryption" is enabled, which allows remote attackers to obtain sensitive information by sniffing the network.
kio/usernotificationhandler.cpp in the POP3 kioslave in kdelibs 4.10.95 before 4.13.3 does not properly generate warning notifications, which allows man-in-the-middle attackers to obtain sensitive information via an invalid certificate.
kpac/script.cpp in KDE kio before 5.32 and kdelibs before 4.14.30 calls the PAC FindProxyForURL function with a full https URL (potentially including Basic Authentication credentials, a query string, or PATH_INFO), which allows remote attackers to obtain sensitive information via a crafted PAC file.
The S/MIME specification allows a Cipher Block Chaining (CBC) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL.
kde-workspace 4.2.0 and plasma-workspace before 5.1.95 allows remote attackers to obtain input events, and consequently obtain passwords, by leveraging access to the X server when the screen is locked.
KDE KMail 19.12.3 (aka 5.13.3) engages in unencrypted POP3 communication during times when the UI indicates that encryption is in use.