CVE-2026-47247 libheif Vulnerable to Heap Information Disclosure via Grid Image Gap + Uninitialized Pixel Plane Allocation
Attackers can leak heap memory, including ASLR-defeating pointers, by uploading crafted AVIF/HEIC files to servers using libheif for image processing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-47247?
CVE-2026-47247 is a high-severity vulnerability in strukturag libheif, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
libheif is a HEIF and AVIF file format decoder and encoder. Prior to version 1.22.0, two bugs in libheif chain to leak process heap memory as visible pixel values in decoded grid images. An attacker who uploads a crafted AVIF/HEIC file to any server-side image processor (WordPress, Sharp/libvips, ImageMagick, etc.) can recover heap data - including library function pointers sufficient to defeat ASLR, or any other secret - from the publicly-downloadable transcoded JPEG/PNG/WebP output. Local attack vectors are also possible. Version 1.22.0 fixes the issue.
Which versions are affected by CVE-2026-47247?
It affects 1 product.
Products include Struktur Libheif.
How do I fix CVE-2026-47247?
Upgrade to a fixed version.
Is CVE-2026-47247 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47247 exists.
Other vulnerabilities in strukturag libheif
Sources
Also known as BELL-CVE-2026-47247, DEBIAN-CVE-2026-47247, ECHO-319a-cd5a-1244, GHSA-2vh6-whr3-cmq3, JLSEC-2026-1096, ROOT-OS-DEBIAN-12-CVE-2026-47247 and 1 more.