SDL_image is a library to load images of various formats as SDL surfaces. In do_layer_surface() in src/IMG_xcf.c, pixel index values from decoded XCF tile data are used directly as colormap indices without validating them against the colormap size (cm_num). A crafted .xcf file with a small colormap and out-of-range pixel indices causes heap out-of-bounds reads of up to 762 bytes past the colormap allocation. Both IMAGE_INDEXED code paths are affected (bpp=1 and bpp=2). The leaked heap bytes are written into the output surface pixel data, making them potentially observable in the rendered image. This vulnerability is fixed with commit 996bf12888925932daace576e09c3053410896f8.
Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:HI:NA:L7.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:LMemory Safety