CVE-2025-5455
HighCVSS 8.4Exploitation Probability (EPSS)
Low risk25th percentile - higher than 25% of all known CVEs
Summary
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).
Risk Assessment
An attacker can remotely crash applications using Qt, leading to service disruption.
Recommendation
Update Qt to version 5.15.19, 6.5.9, 6.8.4, or 6.9.1.
Other vulnerabilities in Qt
See all- CVE-2025-6338Critical
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.
- CVE-2026-9499Medium
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.
- CVE-2025-12385High
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.
- CVE-2025-5992Low
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.
- CVE-2025-5991Low
A Use-After-Free vulnerability in Qt's QHttp2ProtocolHandler in the QtNetwork module affects only HTTP/2 handling. It arises from a race condition between uploading POST request body and simultaneous handling of HTTP errors. Affects only Qt 6.9.0; fixed in Qt 6.9.1.
- CVE-2025-5683Medium
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.
- CVE-2025-4211High
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.
- CVE-2025-3512Medium
A heap-based buffer overflow vulnerability was found in QTextMarkdownImporter in Qt. It occurs when processing a malformed Markdown file. Affects Qt versions 6.8.0 to 6.8.4; versions up to 6.6.0 are unaffected, and the fix is in 6.8.4 and later.
- CVE-2023-37369High
In versions of 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.
- CVE-2023-38197High
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 related to infinite loops in recursive entity expansion.
Original NVD description (English source)
An issue was found in the private API function qDecodeDataUrl() in QtCore, which is used in QTextDocument and QNetworkReply, and, potentially, in user code. If the function was called with malformed data, for example, an URL that contained a "charset" parameter that lacked a value (such as "data:charset,"), and Qt was built with assertions enabled, then it would hit an assertion, resulting in a denial of service (abort). This impacts Qt up to 5.15.18, 6.0.0->6.5.8, 6.6.0->6.8.3 and 6.9.0. This has been fixed in 5.15.19, 6.5.9, 6.8.4 and 6.9.1.

