# CVE-2025-43966: Null dereference in libheif

> A NULL pointer dereference in libheif allows attackers to cause a denial of service via crafted HEIF images.

- **Severity:** Low 2.9 (`CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 20 Apr 2025
- **Updated:** 21 Apr 2025
- **Also known as:** DEBIAN-CVE-2025-43966, ECHO-2b93-9a91-0d00, GHSA-7g9v-7vc7-pmrw

## What is CVE-2025-43966?

CVE-2025-43966 is a low-severity vulnerability in struktur libheif, published on 20 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

libheif before 1.19.6 has a NULL pointer dereference in ImageItem_iden in image-items/iden.cc.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2025-43966?

It affects 1 product.


Products: Struktur Libheif.

## How do I fix CVE-2025-43966?

Upgrade to a fixed version.

## Is CVE-2025-43966 being exploited?

There is no known exploitation of CVE-2025-43966 in the wild and no public exploit code.

## Other vulnerabilities in struktur 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-2025-43966 and fix it if it is affected.

What it is: CVE-2025-43966 is a low-severity vulnerability in struktur libheif, published on 20 Apr 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-43966 in the wild and no public exploit code.

Affected product: struktur 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-2025-43966/ (Markdown: https://insights.sbomify.com/CVE-2025-43966/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-43966
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-43966
- OSV: https://osv.dev/vulnerability/CVE-2025-43966

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-43966/
Summaries are generated and may contain mistakes; the official description above is the record.