CVE-2026-84449

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.19.6, Op_RGB24_32_to_YCbCr::convert_colorspace() stores image-plane strides in an integer width that can overflow for extremely large RGB images created through heif_image_create() and heif_image_add_plane(). The resulting wrapped stride causes the conversion loop in libheif/color-conversion/rgb2yuv.cc to compute an invalid input pointer and read beyond the allocated interleaved plane while heif_context_encode_image() performs RGB-to-YCbCr conversion. This can crash the encoding process. This issue is fixed in version 1.19.6.

• https://github.com/strukturag/libheif/commit/e29953da30eb11aa1762df0bff3b36be4b22fbe3
• https://github.com/strukturag/libheif/releases/tag/v1.19.6
• https://github.com/strukturag/libheif/security/advisories/GHSA-2c3g-p585-8rpq
• https://github.com/strukturag/libheif/security/advisories/GHSA-2c3g-p585-8rpq