libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.1, a crafted uncompressed HEIF image using generic zlib unci full-item compression can crash an application that decodes an advertised tile with heif_image_handle_decode_image_tile(). In libheif/codecs/uncompressed/unc_decoder.cc, unc_decoder::fetch_tile_data() computes a large tile offset and unc_decoder::get_compressed_image_data_uncompressed() validates it with range_start_offset plus range_size. For the last advertised tile (4095, 4095), the addition can wrap to zero, bypass the bounds check, and pass an invalid source pointer and a one-terabyte length to memcpy. The observed result is an out-of-bounds read and process crash; opening the file alone does not trigger the issue because tile decoding is required. This issue is fixed in version 1.23.1.
History

Tue, 18 Aug 2026 21:30:00 +0000

Type Values Removed Values Added
Description libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.1, a crafted uncompressed HEIF image using generic zlib unci full-item compression can crash an application that decodes an advertised tile with heif_image_handle_decode_image_tile(). In libheif/codecs/uncompressed/unc_decoder.cc, unc_decoder::fetch_tile_data() computes a large tile offset and unc_decoder::get_compressed_image_data_uncompressed() validates it with range_start_offset plus range_size. For the last advertised tile (4095, 4095), the addition can wrap to zero, bypass the bounds check, and pass an invalid source pointer and a one-terabyte length to memcpy. The observed result is an out-of-bounds read and process crash; opening the file alone does not trigger the issue because tile decoding is required. This issue is fixed in version 1.23.1.
Title libheif: Out-of-bounds read in uncompressed unci tile range slicing
Weaknesses CWE-125
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-18T21:20:24.933Z

Reserved: 2026-07-13T18:37:08.488Z

Link: CVE-2026-62292

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-18T22:17:03.023

Modified: 2026-08-18T22:17:03.023

Link: CVE-2026-62292

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-19T00:30:04Z