libvips is a fast image processing library with low memory needs. Prior to version 8.18.3, libvips built with libultrahdr support can incorrectly size an output buffer in libvips/foreign/uhdrsave.c within vips_foreign_save_uhdr_set_raw_hdr when a pipeline enlarges an incoming JPEG to a very large output before encoding a gain map through VipsForeignSaveUhdr. The undersized allocation can cause a heap buffer over-read that may disclose adjacent data or crash the process. This issue is fixed in version 8.18.3.
Buffer Over-read The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.