CVE-2026-9499

Name of the Vulnerable Software and Affected Versions Qt versions 4.x Qt versions 5.x Qt versions 6.0.0 and later

Description An out-of-bounds read occurs in the codecForName() function of QTextCodec. This happens when the function is called with a QByteArray that is not NUL-terminated, such as those created using QByteArray::fromRawData(), causing the codec-name matching routine to read past the end of the buffer. This can lead to the selection of an incorrect text codec or a process crash resulting in a denial of service if unmapped memory is accessed. The over-read is limited to the length of the longest codec-name candidate and does not disclose data as bytes are only compared against a fixed internal list of codec names.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability. Avoid passing non-NUL-terminated QByteArray objects to the codecForName() function.