CVE-2026-47178 libheif has Heap Out Of Bounds Write in unci subsystem
A crafted HEIF file triggers a heap out-of-bounds write in libheif, allowing attackers to overwrite vtable pointers and achieve arbitrary code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-47178?
CVE-2026-47178 is a medium-severity memory corruption vulnerability in strukturag libheif, published on 21 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.19.0 through 1.21.2, a crafted HEIF file (uncompressed `unci` codec, tiled, component-interleaved, 4:2:0) triggers a heap out-of-bounds write in libheif's uncompressed tile decoder. The write overwrites the C++ vtable pointer of an adjacent `unc_decoder_component_interleave` object; the next virtual call dispatches to an attacker-chosen address. Version 1.22.0 patches the issue.
Weakness: CWE-787
Which versions are affected by CVE-2026-47178?
It affects 1 product.
Products include Struktur Libheif.
How do I fix CVE-2026-47178?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-47178 being exploited?
There is no known exploitation of CVE-2026-47178 in the wild and no public exploit code.
Other vulnerabilities in strukturag libheif
Sources
Also known as DEBIAN-CVE-2026-47178, ECHO-8449-98f8-ce75, GHSA-5x55-x5pf-9c6g, JLSEC-2026-1095, ROOT-OS-DEBIAN-11-CVE-2026-47178, UBUNTU-CVE-2026-47178 and 1 more.