A flaw was discovered in GEGL through 0.3.32. The gegl_tile_backend_swap_constructed function in buffer/gegl-tile-backend-swap.c allows remote attackers to cause a denial of service (write access violation) or possibly have unspecified other impact via a malformed PNG file that is mishandled during a call to the babl_format_get_bytes_per_pixel function in babl-format.c in babl 0.1.46.
Created gegl tracking bugs for this issue:
Affects: fedora-all [bug 1570186]
Created gegl03 tracking bugs for this issue:
Affects: fedora-all [bug 1609102]
As an upstream contributor to GEGL, and a downstream Fedora packager, I am surprised that this managed to bubble all the way up to becoming a CVE!
As far as I can make out, this was originally filed as https://bugzilla.gnome.org/show_bug.cgi?id=795249, which got migrated to https://gitlab.gnome.org/GNOME/gegl/issues/65 Note the complete lack of response from the reporter after the initial submission. Anyway, I have added a comment to the Gitlab issue that should clarify the situation a bit more.
In short, this is a known problem that's being worked on. It's not possible to fix it with a small localized fix that can be carried downstream.