An issue was discovered in Qt 5.11. A malformed PPM image causes a division by zero and a crash in qppmhandler.cpp.
https://usn.ubuntu.com/4275-1/
https://lists.debian.org/debian-lts-announce/2020/09/msg00024.html
https://lists.debian.org/debian-lts-announce/2020/09/msg00023.html
https://bugreports.qt.io/browse/QTBUG-69449
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00080.html
http://blog.qt.io/blog/2018/12/04/qt-5-11-3-released-important-security-updates/