An issue was discovered in CImg through v.220. A heap-based buffer over-read in load_bmp in CImg.h occurs when loading a crafted bmp image, a different vulnerability than CVE-2018-7588. This is in a "16 colors" case, aka case 4.
CWE-125 - Out-of-Bounds Read
Out-of-bounds read is a vulnerability that allows access to memory beyond the authorized accessible location. Such a vulnerability compromises the confidentiality of the trusted environment in the application and enables an attacker to launch further attacks by leveraging the exposed information.