CVE-2026-62289

libheif: Integer underflow in Fraction constructor via double clap transform application

Published Aug 18, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted HEIF or AVIF file containing a clean aperture box can reduce an image dimension to zero and crash or corrupt tiling results when heif_image_handle_get_image_tiling(handle, 1, &tiling) is called. ImageItem::get_heif_image_tiling() returns already transformed dimensions, and process_image_transformations_on_tiling() applies the clean aperture transformation again. The second application passes zero to Box_clap::left_rounded(0), where image_width minus one underflows and constructs Fraction(0xFFFFFFFF, 2). Debug builds reach an assertion and abort, while release builds can return a corrupt crop and zero-width tiling result. The affected implementation spans libheif/image-items/image_item.cc, libheif/context.cc, and libheif/box.cc. This issue is fixed in version 1.23.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6417-1 libheif security update
Ubuntu USN Ubuntu USN USN-8649-1 libheif vulnerabilities
Ubuntu USN Ubuntu USN USN-8683-1 libheif vulnerabilities
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Struktur
Struktur libheif
Vendors & Products Struktur
Struktur libheif
Type Values Removed Values Added
Description libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted HEIF or AVIF file containing a clean aperture box can reduce an image dimension to zero and crash or corrupt tiling results when heif_image_handle_get_image_tiling(handle, 1, &tiling) is called. ImageItem::get_heif_image_tiling() returns already transformed dimensions, and process_image_transformations_on_tiling() applies the clean aperture transformation again. The second application passes zero to Box_clap::left_rounded(0), where image_width minus one underflows and constructs Fraction(0xFFFFFFFF, 2). Debug builds reach an assertion and abort, while release builds can return a corrupt crop and zero-width tiling result. The affected implementation spans libheif/image-items/image_item.cc, libheif/context.cc, and libheif/box.cc. This issue is fixed in version 1.23.1.
Title libheif: Integer underflow in Fraction constructor via double clap transform application
Weaknesses CWE-191
CWE-617
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Aug 19, 2026, 4:51 PM
Reserved
Jul 13, 2026, 6:37 PM
Status
Deferred
Published
Aug 18, 2026, 10:17 PM
Modified
Oct 22, 2026, 4:09 PM