CVE-2025-5991

Incomplete cleanup in Qt Network's Schannel support on Windows can lead to a Denial of Service over time. Affects Qt from 5.15.0 through 6.8.3 and from 6.9.0 before 6.9.2.

In the HTTP2 implementation in Qt before 5.15.17, 6.2.11, 6.5.4, and 6.6.2, there is an incorrect HPack integer overflow check in hpacktable.cpp.

Uncontrolled recursion in QXmlStreamReader::readElementText() in Qt Group Qt allows attackers to cause a denial of service (application crash via stack exhaustion) via a crafted XML document.

QDomDocument XML parsing is vulnerable to a remotely-triggerable denial-of-service crash when processing untrusted input.

An out-of-bounds read vulnerability in QTextCodec::codecForName() in Qt. When called with a non-NUL-terminated QByteArray, the codec-name matching routine reads past the buffer. This usually results in incorrect codec selection; worst case, it causes a crash (DoS). Affects Qt5Compat module from Qt 6.0.0 and Qt Core in Qt 4.x and 5.x.

In Qt Quick, the Text component lacks validation of width and height in the <img> tag, potentially causing excessive resource allocation and application unresponsiveness. Affects Qt from 5.0.0 through 6.10.0.

A vulnerability in Qt's QColorTransferGenericFunction causes a denial of service when passing values outside the expected range, e.g., when processing a specially crafted ICC profile via QColorSpace::fromICCProfile. Affects Qt from 6.6.0 through 6.8.3 and from 6.9.0 through 6.9.1; fixed in 6.8.4 and 6.9.2.

A vulnerability in Qt causes a crash when loading a specially crafted ICNS image file via QImage. Affects Qt versions 6.3.0 through 6.5.9, 6.6.0 through 6.8.4, and 6.9.0. Fixed in 6.5.10, 6.8.5, and 6.9.1.

An issue was found in the private API function qDecodeDataUrl() in QtCore, used in QTextDocument and QNetworkReply. Calling it with malformed data, e.g., a URL with a "charset" parameter lacking a value, triggers an assertion and aborts the program (denial of service).

A symlink attack vulnerability was found in the Qt corelib module on Windows via QFileSystemEngine. The use of GetTempPath API allows manipulation of temporary file paths, potentially leading to unauthorized access and privilege escalation.