In Poppler through 0.76.1, there is a heap-based buffer over-read in JPXStream::init in JPEG2000Stream.cc via data with inconsistent heights or widths.
https://usn.ubuntu.com/4042-1/
https://lists.debian.org/debian-lts-announce/2020/07/msg00018.html
https://lists.debian.org/debian-lts-announce/2019/06/msg00002.html
https://gitlab.freedesktop.org/poppler/poppler/issues/768