CVE-2026-47247CWE-200CWE-226CWE-682CWE-908

libheif Vulnerable to Heap Information Disclosure via Grid Image Gap + Uninitialized Pixel Plane Allocation

High · published July 21, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
37.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00448 · 37.5th percentile
Weaknesses
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor; CWE-226 · Sensitive Information in Resource Not Removed Before Reuse; CWE-682 · Incorrect Calculation; CWE-908 · Use of Uninitialized Resource
Published
2026-07-21T21:16Z
EPSS history
Timeline
  • 21 JUL 21:16Z
    libheif Vulnerable to Heap Information Disclosure via Grid Image Gap + Uninitialized Pixel Plane Allocation
    cvelistv5