https://gitlab.gnome.org/GNOME/gimp/-/work_items/16492

fli_header.width and fli_header.height are gushort (uint16). The expression
fb  = g_malloc (fli_header.width * fli_header.height);
ofb = g_malloc (fli_header.width * fli_header.height);


performs the multiplication after C integer promotion to int. When both values are 65535 the product 4,294,836,225 exceeds INT_MAX (2,147,483,647) → undefined behavior. UBSan detects this and the plug-in aborts.
Affected code
/* plug-ins/file-fli/fli-gimp.c:541-546 */
image = gimp_image_new (fli_header.width, fli_header.height, GIMP_INDEXED);

fb  = g_malloc (fli_header.width * fli_header.height);
ofb = g_malloc (fli_header.width * fli_header.height);


File: plug-ins/file-fli/fli-gimp.c:545 (and the mirror at L546, L805, L806)
Version: GIMP 3.2.4