The named pipes in qtsingleapp in Qt 5.x, as used in qBittorrent and SugarSync, are configured for remote access and allow remote attackers to cause a denial of service (application crash) via an unspecified string.

An issue has been fixed in Qt versions 5.14.0 where QPluginLoader attempts to load plugins relative to the working directory, allowing attackers to execute arbitrary code via crafted files.

An issue was discovered in Qt through 5.12.9, and 5.13.x through 5.15.x before 5.15.1. readxbmbody in gui/image/qxbmhandler.cpp has a buffer over-read.

Qt 5.12.2 through 5.14.2, as used in unofficial builds of Mumble 1.3.0 and other products, mishandles OpenSSL's error queue, which can cause a denial of service to QSslSocket users. Because errors leak in unrelated TLS sessions, an unrelated session may be disconnected when any handshake fails. (Mumble 1.3.1 is not affected, regardless of the Qt version.)