# ImageMagick stack buffer overflow in MNG encoder

Source: https://junglewise.ai/threats/imagemagick-stack-buffer-overflow-in-mng-encoder-8421fbc3  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-14. Updated: 2026-05-11  
License: CC BY 4.0 with a link back

Severity: medium · CVSS 6.9 · Published 2026-04-14

ImageMagick, a widely used suite for editing and converting digital images, contains a vulnerability in how it handles certain multi-frame image files. An attacker could provide a specially crafted image with an oversized color palette to cause a system crash or potentially execute unauthorized code. This could lead to service disruptions or unauthorized access to data on systems that process user-uploaded images.

Technologies: [Magick.NET-Q16-AnyCPU (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-anycpu), [Magick.NET-Q16-arm64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-arm64), [Magick.NET-Q16-HDRI-AnyCPU (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-hdri-anycpu), [Magick.NET-Q16-HDRI-arm64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-hdri-arm64), [Magick.NET-Q16-HDRI-OpenMP-arm64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-hdri-openmp-arm64), [Magick.NET-Q16-HDRI-OpenMP-x64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-hdri-openmp-x64), [Magick.NET-Q16-HDRI-x64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-hdri-x64), [Magick.NET-Q16-HDRI-x86 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-hdri-x86), [Magick.NET-Q16-OpenMP-arm64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-openmp-arm64), [Magick.NET-Q16-OpenMP-x64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-openmp-x64), [Magick.NET-Q16-x64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-x64), [Magick.NET-Q16-x86 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-x86), [Magick.NET-Q8-AnyCPU (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q8-anycpu), [Magick.NET-Q8-arm64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q8-arm64), [Magick.NET-Q8-OpenMP-arm64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q8-openmp-arm64), [Magick.NET-Q8-OpenMP-x64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q8-openmp-x64), [Magick.NET-Q8-x64 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q8-x64), [Magick.NET-Q8-x86 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q8-x86). Vendors: [NuGet](https://junglewise.ai/threats/vendors/nuget).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Medium severity, with a CVSS score of 6.9, published 14 April 2026.

**Which products and versions are affected?** Magick.NET-Q16-AnyCPU (NuGet) < 14.12.0; Magick.NET-Q16-arm64 (NuGet) < 14.12.0; Magick.NET-Q16-HDRI-AnyCPU (NuGet) < 14.12.0; Magick.NET-Q16-HDRI-arm64 (NuGet) < 14.12.0; and 14 more.

**Is there a fix for This vulnerability?** A patch was published on 2026-04-14. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked with local access, in a software library.

**Am I affected?** Check whether you run Magick.NET-Q16-AnyCPU (NuGet), Magick.NET-Q16-arm64 (NuGet), Magick.NET-Q16-HDRI-AnyCPU (NuGet) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stack-based buffer overflow (CWE-121) exists in the ImageMagick MNG encoder. The vulnerability is caused by an incomplete fix for a previous issue, where the encoder fails to properly validate the size of palettes in multi-frame images. A local attacker can exploit this by providing a malicious image file, potentially leading to arbitrary code execution or a denial-of-service (DoS) condition. The vulnerability is addressed in Magick.NET version 14.12.0.

## Affected products

- ImageMagick Magick.NET-Q16-AnyCPU < 14.12.0
- ImageMagick Magick.NET-Q16-HDRI-AnyCPU < 14.12.0
- ImageMagick Magick.NET-Q16-HDRI-OpenMP-arm64 < 14.12.0
- ImageMagick Magick.NET-Q16-HDRI-OpenMP-x64 < 14.12.0
- ImageMagick Magick.NET-Q16-HDRI-arm64 < 14.12.0
- ImageMagick Magick.NET-Q16-HDRI-x64 < 14.12.0
- ImageMagick Magick.NET-Q16-HDRI-x86 < 14.12.0
- ImageMagick Magick.NET-Q16-OpenMP-arm64 < 14.12.0
- ImageMagick Magick.NET-Q16-OpenMP-x64 < 14.12.0
- ImageMagick Magick.NET-Q16-arm64 < 14.12.0
- ImageMagick Magick.NET-Q16-x64 < 14.12.0
- ImageMagick Magick.NET-Q16-x86 < 14.12.0
- ImageMagick Magick.NET-Q8-AnyCPU < 14.12.0
- ImageMagick Magick.NET-Q8-OpenMP-arm64 < 14.12.0
- ImageMagick Magick.NET-Q8-OpenMP-x64 < 14.12.0
- ImageMagick Magick.NET-Q8-arm64 < 14.12.0
- ImageMagick Magick.NET-Q8-x64 < 14.12.0
- ImageMagick Magick.NET-Q8-x86 < 14.12.0

## Timeline

- 2026-04-13: disclosed
- 2026-04-14: advisory
- 2026-04-14: patched

## References

- [https://api.github.com/users/unbengable12](https://api.github.com/users/unbengable12)
- [https://github.com/unbengable12](https://github.com/unbengable12)
- [https://api.github.com/users/unbengable12/gists%7B/gist_id%7D](https://api.github.com/users/unbengable12/gists%7B/gist_id%7D)
- [https://api.github.com/users/unbengable12/repos](https://api.github.com/users/unbengable12/repos)
- [https://avatars.githubusercontent.com/u/100500028?v=4](https://avatars.githubusercontent.com/u/100500028?v=4)
- [https://api.github.com/users/unbengable12/events%7B/privacy%7D](https://api.github.com/users/unbengable12/events%7B/privacy%7D)

## Related threats

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- [ImageMagick heap buffer overwrite in morphology operation](https://junglewise.ai/threats/cve-2026-62343-imagemagick-heap-buffer-overwrite-in-morphology-operation)
- [ImageMagick memory leak in magick CLI via invalid options](https://junglewise.ai/threats/cve-2026-66011-imagemagick-memory-leak-in-magick-cli-via-invalid-options)
- [ImageMagick memory leak in TIFF encoder](https://junglewise.ai/threats/cve-2026-61872-imagemagick-memory-leak-in-tiff-encoder)