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.

QXmlSimpleReader in Qt before 5.2 allows context-dependent attackers to cause a denial of service (memory consumption) via an XML Entity Expansion (XEE) attack.

SQL injection vulnerability in Quassel IRC before 0.9.1, when Qt 4.8.5 or later and PostgreSQL 8.2 or later are used, allows remote attackers to execute arbitrary SQL commands via a \ (backslash) in a message.

A security flaw was found in the way QSharedMemory class implementation of the Qt toolkit created shared memory segments (they were created with world-readable and world-writeable permissions). A local attacker could use this flaw to read or alter content of particular shared memory segment, possibly leading to their ability to obtain sensitive information or influence behaviour of shared memory segment reader process.