Reachable assertion in libheif - CVE-2026-84450

Vulnerability identifier: #VU146729

CSH Severity: Low

CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-84450

CWE-ID: CWE-617

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to reachable assertion in Fraction::Fraction and Box_clap clap geometry helpers when parsing a crafted AVIF image with a clap property and oversized ispe dimensions. A remote attacker can supply a specially crafted image file to cause a denial of service.

The issue is triggered in assert-enabled builds via the public C API during heif_image_handle_get_image_tiling(), and user interaction is required to open or process the crafted image.

libheif
Debian Linux
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
Desktop Applications Module
SUSE Package Hub 15
libheif-rav1e-debuginfo
libheif-ffmpeg
libheif-ffmpeg-debuginfo
gdk-pixbuf-loader-libheif
gdk-pixbuf-loader-libheif-debuginfo
libheif-devel
libheif1
libheif-aom-debuginfo
libheif-rav1e
libheif-jpeg-debuginfo
libheif-dav1d-debuginfo
libheif1-debuginfo
libheif-jpeg
libheif-debugsource
libheif-aom
libheif-dav1d
libheif (Debian package)

Install security update from vendor's website.

libheif - update to 1.23.3
libheif-rav1e-debuginfo - update to 1.23.4-150700.3.21.1
libheif-ffmpeg - update to 1.23.4-150700.3.21.1
libheif-ffmpeg-debuginfo - update to 1.23.4-150700.3.21.1
gdk-pixbuf-loader-libheif - update to 1.23.4-150700.3.21.1
gdk-pixbuf-loader-libheif-debuginfo - update to 1.23.4-150700.3.21.1
libheif-devel - update to 1.23.4-150700.3.21.1
libheif1 - update to 1.23.4-150700.3.21.1
libheif-aom-debuginfo - update to 1.23.4-150700.3.21.1
libheif-rav1e - update to 1.23.4-150700.3.21.1
libheif-jpeg-debuginfo - update to 1.23.4-150700.3.21.1
libheif-dav1d-debuginfo - update to 1.23.4-150700.3.21.1
libheif1-debuginfo - update to 1.23.4-150700.3.21.1
libheif-jpeg - update to 1.23.4-150700.3.21.1
libheif-debugsource - update to 1.23.4-150700.3.21.1
libheif-aom - update to 1.23.4-150700.3.21.1
libheif-dav1d - update to 1.23.4-150700.3.21.1
libheif (Debian package) - update to 1.23.4-1~deb13u1

• https://github.com/strukturag/libheif/security/advisories/GHSA-gh5q-69gg-c964

• Multiple vulnerabilities in libheif
• Debian update for libheif
• SUSE update for libheif