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.

An issue was discovered in Qt before 5.15.14, 6.x before 6.2.9, and 6.3.x through 6.5.x before 6.5.1. Qt Network incorrectly parses the strict-transport-security (HSTS) header, allowing unencrypted connections to be established, even when explicitly prohibited by the server. This happens if the case used for this header does not exactly match.

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 before 6.4.3 allows a denial of service via a crafted string when the SQL ODBC driver plugin is used and the size of SQLTCHAR is 4. The affected versions are 5.x before 5.15.13, 6.x before 6.2.8, and 6.3.x before 6.4.3.

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

In Qt 5.9.x through 5.15.x before 5.15.9 and 6.x before 6.2.4 on Linux and UNIX, QProcess could execute a binary from the current working directory when not found in the PATH.

Qt 5.x before 5.15.6 and 6.x through 6.1.2 has an out-of-bounds write in QOutlineMapper::convertPath (called from QRasterPaintEngine::fill and QPaintEngineEx::stroke).