# CVE-2026-47254: libheif Has Heap Buffer Overflow in `Track::get_next_sample_raw_data()` -- OOB Chunk Vector Access

> A heap buffer overflow in libheif allows attackers to execute arbitrary code or cause denial of service via crafted HEIF/AVIF files.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H`)
- **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:** Yes
- **Published:** 21 Jul 2026
- **Updated:** 22 Jul 2026
- **Also known as:** BELL-CVE-2026-47254, DEBIAN-CVE-2026-47254, GHSA-wqjg-4x9g-6cvg, JLSEC-2026-1098, UBUNTU-CVE-2026-47254

## What is CVE-2026-47254?

CVE-2026-47254 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. Prior to version 1.22.0, `Track::init_sample_timing_table()` in `libheif/sequences/track.cc` stores an out-of-bounds chunk index (`m_chunks.size()`) into `m_presentation_timeline` when the number of chunks defined in the `stco` box is less than the number of samples in `stsz`. A subsequent call to `heif_track_get_next_raw_sequence_sample()` reads `m_chunks[chunk_idx]` with that OOB index, causing a heap-buffer-overflow. Version 1.22.0 fixes the issue.

Weakness: CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-47254?

It affects 1 product.


Products: Struktur Libheif.

## How do I fix CVE-2026-47254?

Upgrade to a fixed version.

## Is CVE-2026-47254 being exploited?

There is no known exploitation of CVE-2026-47254 in the wild and no public exploit code.

## 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-2026-47254 and fix it if it is affected.

What it is: CVE-2026-47254 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.
Exploitation: There is no known exploitation of CVE-2026-47254 in the wild and no public exploit code.

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-2026-47254/ (Markdown: https://insights.sbomify.com/CVE-2026-47254/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47254
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47254
- OSV: https://osv.dev/vulnerability/CVE-2026-47254

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47254/
Summaries are generated and may contain mistakes; the official description above is the record.