The UTF-8 decoder in codecs/qutfcodec.cpp in Qt 3.3.8 and 4.2.3 does not reject long UTF-8 sequences as required by the standard, which allows remote attackers to conduct cross-site scripting (XSS) and directory traversal attacks via long sequences that decode to dangerous metacharacters.
Integer overflow in Qt 3.3 before 3.3.7, 4.1 before 4.1.5, and 4.2 before 4.2.1, as used in the KDE khtml library, kdelibs 3.1.3, and possibly other packages, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted pixmap image.