An issue was discovered in HTTP2 in Qt before 5.15.18, 6.x before 6.2.13, 6.3.x through 6.5.x before 6.5.7, and 6.6.x through 6.7.x before 6.7.3. Code to make security-relevant decisions about an established connection may execute too early, because the encrypted() signal has not yet been emitted and processed..

An issue was discovered in the HTTP2 implementation in Qt before 5.15.17, 6.x before 6.2.11, 6.3.x through 6.5.x before 6.5.4, and 6.6.x before 6.6.2. network/access/http2/hpacktable.cpp has an incorrect HPack integer overflow check.

An issue was discovered in Qt before 5.15.16, 6.x before 6.2.10, and 6.3.x through 6.5.x before 6.5.3 on Windows. When using the GDI font engine, if a corrupted font is loaded via QFontDatabase::addApplicationFont{FromData], then it can cause the application to crash because of missing length checks.

In Qt before 5.15.15, 6.x before 6.2.9, and 6.3.x through 6.5.x before 6.5.2, there can be an application crash in QXmlStreamReader via a crafted XML string that triggers a situation in which a prefix is greater than a length.

An issue was discovered in Qt before 5.15.15, 6.x before 6.2.10, and 6.3.x through 6.5.x before 6.5.3. There are infinite loops in recursive entity expansion.

An issue was discovered in Qt before 5.15.15, 6.x before 6.2.9, and 6.3.x through 6.5.x before 6.5.2. Certificate validation for TLS does not always consider whether the root of a chain is a configured CA certificate.

An issue was discovered in Qt before 5.15.15, 6.x before 6.2.9, and 6.3.x through 6.5.x before 6.5.1. When a SVG file with an image inside it is rendered, a QTextLayout buffer overflow can be triggered.

In Qt before 5.15.14, 6.0.x through 6.2.x before 6.2.9, and 6.3.x through 6.5.x before 6.5.1, QtSvg QSvgFont m_unitsPerEm initialization is mishandled.

Qt through 5.15.8 and 6.x through 6.2.3 can load system library files from an unintended working directory.

Uncontrolled search path in the QT Library before 5.14.0, 5.12.7 and 5.9.10 may allow an authenticated user to potentially enable elevation of privilege via local access.

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

In Qt through 5.14.1, the WebSocket implementation accepts up to 2GB for frames and 2GB for messages. Smaller limits cannot be configured. This makes it easier for attackers to cause a denial of service (memory consumption).

An issue was discovered in Qt before 5.11.3. QBmpHandler has a buffer overflow via BMP data.

An issue was discovered in Qt before 5.11.3. There is QTgaFile Uncontrolled Resource Consumption.

An issue was discovered in Qt before 5.11.3. A malformed GIF image causes a NULL pointer dereference in QGifHandler resulting in a segmentation fault.

An issue was discovered in Qt before 5.11.3. A malformed SVG image causes a segmentation fault in qsvghandler.cpp.

The Google V8 engine, as used in Google Chrome before 44.0.2403.89 and QtWebEngineCore in Qt before 5.5.1, allows remote attackers to cause a denial of service (memory corruption) or execute arbitrary code via a crafted web site.

The GIF decoder in QtGui in Qt before 5.3 allows remote attackers to cause a denial of service (NULL pointer dereference) via invalid width and height values in a GIF image.

The QSslSocket::sslErrors function in Qt before 4.6.5, 4.7.x before 4.7.6, 4.8.x before 4.8.5, when using certain versions of openSSL, uses an "incompatible structure layout" that can read memory from the wrong location, which causes Qt to report an incorrect error when certificate validation fails and might cause users to make unsafe security decisions to accept a certificate.

The XMLHttpRequest object in Qt before 4.8.4 enables http redirection to the file scheme, which allows man-in-the-middle attackers to force the read of arbitrary local files and possibly obtain sensitive information via a file: URL to a QML application.