libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and below, a crafted 792-byte HEIF sequence file with samples_per_chunk=0 in the stsc box causes an unsigned integer underflow in the Chunk constructor (m_last_sample = 0 + 0 - 1 = UINT32_MAX), mapping all samples to an empty chunk and resulting in a denial of service. When any sample is accessed, the library reads from index 0 of an empty std::vector, causing a guaranteed SEGV (null-page read). The file parses successfully without producing an error; the crash occurs on the first frame access. This issue has been fixed in version 1.22.0.
libheif is an HEIF and AVIF file format decoder and encoder. Prior to version 1.21.0, a crafted HEIF that exercises the overlay image item path triggers a heap buffer over-read in `HeifPixelImage::overlay()`. The function computes a negative row length (likely from an unclipped overlay rectangle or invalid offsets), which then underflows when converted to `size_t` and is passed to `memcpy`, causing a very large read past the end of the source plane and a crash. Version 1.21.0 contains a patch. As a workaround, avoid decoding images using `iovl` overlay boxes.
libheif before 1.19.6 has a NULL pointer dereference in ImageItem_Grid::get_decoder in image-items/grid.cc because a grid image can reference a nonexistent image item.
An issue was discovered in heif::Box_iref::get_references in libheif 1.4.0, allows attackers to cause a Denial of Service or possibly other unspecified impact due to an invalid memory read.
libheif 1.4.0 has a use-after-free in heif::HeifContext::Image::set_alpha_channel in heif_context.h because heif_context.cc mishandles references to non-existing alpha images.