# 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.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Jul 2026
- **Updated:** 22 Jul 2026
- **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, UBUNTU-CVE-2026-47247

## 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.

Weakness: CWE-908 (Use of Uninitialized Resource), CWE-682 (Incorrect Calculation), CWE-226 (Sensitive Information in Resource Not Removed Before Reuse), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-47247?

It affects 1 product.


Products: 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

- [CVE-2026-32740](https://insights.sbomify.com/CVE-2026-32740/): libheif: Heap-Buffer-Overflow Write in Grid Tile Chroma Compositing (high 8.8)
- [CVE-2023-49460](https://insights.sbomify.com/CVE-2023-49460/): Null dereference in n/a (high 8.8)
- [CVE-2023-49462](https://insights.sbomify.com/CVE-2023-49462/): Null dereference in n/a (high 8.8)
- [CVE-2023-49463](https://insights.sbomify.com/CVE-2023-49463/): Null dereference in n/a (high 8.8)
- [CVE-2023-49464](https://insights.sbomify.com/CVE-2023-49464/): Null dereference in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47247 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-47247 exists.

Affected product: strukturag libheif. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-47247/ (Markdown: https://insights.sbomify.com/CVE-2026-47247/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47247
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47247
- OSV: https://osv.dev/vulnerability/CVE-2026-47247

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47247/
Summaries are generated and may contain mistakes; the official description above is the record.