# CVE-2026-25794: ImageMagick heap overflow in WriteUHDRImage

Source: https://junglewise.ai/threats/cve-2026-25794-imagemagick-heap-overflow-in-writeuhdrimage  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-24. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-25794 · Severity: high · CVSS 8.2 · Published 2026-02-24

ImageMagick is a widely used open-source tool for creating, editing, and converting digital images. A vulnerability in how it handles Ultra High Dynamic Range (UHDR) images could allow an attacker to crash the software or potentially execute unauthorized code by providing a specially crafted image with very large dimensions. This could lead to service disruptions or unauthorized access to systems that automatically process user-uploaded images.

Technologies: [ImageMagick](https://junglewise.ai/threats/technologies/imagemagick), [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-OpenMP-x86 (NuGet)](https://junglewise.ai/threats/technologies/magick-net-q16-openmp-x86), [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: [ImageMagick](https://junglewise.ai/threats/vendors/imagemagick), [NuGet](https://junglewise.ai/threats/vendors/nuget).

## Quick answers

**Is CVE-2026-25794 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-25794 being exploited in the wild.

**How severe is CVE-2026-25794?** High severity, with a CVSS score of 8.2, published 24 February 2026.

**Which products and versions are affected?** Magick.NET-Q16-AnyCPU (NuGet) ECOSYSTEM:introduced=0,fixed=14.10.3; Magick.NET-Q16-arm64 (NuGet) ECOSYSTEM:introduced=0,fixed=14.10.3; Magick.NET-Q16-HDRI-AnyCPU (NuGet) ECOSYSTEM:introduced=0,fixed=14.10.3; Magick.NET-Q16-HDRI-arm64 (NuGet) ECOSYSTEM:introduced=0,fixed=14.10.3; and 15 more.

**Is there a fix for CVE-2026-25794?** Yes. Magick.NET-Q16-AnyCPU (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-arm64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-HDRI-AnyCPU (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-HDRI-arm64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-HDRI-OpenMP-arm64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-HDRI-OpenMP-x64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-HDRI-x64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-HDRI-x86 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-OpenMP-arm64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-OpenMP-x64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-OpenMP-x86 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-x64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q16-x86 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q8-AnyCPU (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q8-arm64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q8-OpenMP-arm64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q8-OpenMP-x64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q8-x64 (NuGet): upgrade to 14.10.3 or later; Magick.NET-Q8-x86 (NuGet): upgrade to 14.10.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-25794 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-25794?** Check whether you run ImageMagick, Magick.NET-Q16-AnyCPU (NuGet), Magick.NET-Q16-arm64 (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.

## How to fix

- Magick.NET-Q16-AnyCPU (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-AnyCPU --version 14.10.3
  ```

- Magick.NET-Q16-arm64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-arm64 --version 14.10.3
  ```

- Magick.NET-Q16-HDRI-AnyCPU (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-HDRI-AnyCPU --version 14.10.3
  ```

- Magick.NET-Q16-HDRI-arm64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-HDRI-arm64 --version 14.10.3
  ```

- Magick.NET-Q16-HDRI-OpenMP-arm64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-HDRI-OpenMP-arm64 --version 14.10.3
  ```

- Magick.NET-Q16-HDRI-OpenMP-x64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-HDRI-OpenMP-x64 --version 14.10.3
  ```

- Magick.NET-Q16-HDRI-x64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-HDRI-x64 --version 14.10.3
  ```

- Magick.NET-Q16-HDRI-x86 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-HDRI-x86 --version 14.10.3
  ```

- Magick.NET-Q16-OpenMP-arm64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-OpenMP-arm64 --version 14.10.3
  ```

- Magick.NET-Q16-OpenMP-x64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-OpenMP-x64 --version 14.10.3
  ```

- Magick.NET-Q16-OpenMP-x86 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-OpenMP-x86 --version 14.10.3
  ```

- Magick.NET-Q16-x64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-x64 --version 14.10.3
  ```

- Magick.NET-Q16-x86 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q16-x86 --version 14.10.3
  ```

- Magick.NET-Q8-AnyCPU (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q8-AnyCPU --version 14.10.3
  ```

- Magick.NET-Q8-arm64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q8-arm64 --version 14.10.3
  ```

- Magick.NET-Q8-OpenMP-arm64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q8-OpenMP-arm64 --version 14.10.3
  ```

- Magick.NET-Q8-OpenMP-x64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q8-OpenMP-x64 --version 14.10.3
  ```

- Magick.NET-Q8-x64 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q8-x64 --version 14.10.3
  ```

- Magick.NET-Q8-x86 (NuGet): upgrade to 14.10.3 or later

  ```sh
  dotnet add package Magick.NET-Q8-x86 --version 14.10.3
  ```


## Technical details

An integer overflow vulnerability exists in ImageMagick's `WriteUHDRImage` function within `coders/uhdr.c`. The software uses 32-bit signed integer arithmetic to calculate the pixel buffer size; when processing images with extremely large dimensions, this multiplication overflows, resulting in an undersized heap allocation. Subsequent write operations then exceed the buffer boundaries, leading to a heap-based buffer overflow. A remote attacker can exploit this by providing a malicious UHDR image, potentially causing a denial-of-service (crash) or arbitrary code execution. The issue is fixed in version 7.1.2-15.

## Affected products

- ImageMagick ImageMagick < 7.1.2-15
- Red Hat Enterprise Linux 6 affected

## Identifiers

- CVE-2026-25794
- GHSA-vhqj-f5cj-9x8h

## Timeline

- 2026-02-23: disclosed: Initial disclosure by GitHub/ImageMagick
- 2026-02-23: patched: Version 7.1.2-15 released with fix
- 2026-02-24: advisory: NVD and Red Hat advisories published

## References

- [https://github.com/ImageMagick/ImageMagick/security/advisories/GHSA-vhqj-f5cj-9x8h](https://github.com/ImageMagick/ImageMagick/security/advisories/GHSA-vhqj-f5cj-9x8h)
- [https://access.redhat.com/security/cve/CVE-2026-25794](https://access.redhat.com/security/cve/CVE-2026-25794)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2442110](https://bugzilla.redhat.com/show_bug.cgi?id=2442110)
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25794.json](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25794.json)

## Related threats

- [ImageMagick infinite loop in SVG decoder](https://junglewise.ai/threats/cve-2026-123273-imagemagick-before-7-1-2-35-and-6-9-13-60-contains-an-infinite)
- [ImageMagick memory leak in XMP profile handling](https://junglewise.ai/threats/cve-2026-116155-imagemagick-before-6-9-13-58-and-7-x-before-7-1-2-33-contains-a)
- [ImageMagick memory leak in XML parsing depth limit](https://junglewise.ai/threats/cve-2026-116154-imagemagick-before-6-9-13-58-and-7-x-before-7-1-2-33-contains-a)
- [ImageMagick memory leak in MAT decoder](https://junglewise.ai/threats/cve-2026-116152-imagemagick-before-7-1-2-33-contains-a-memory-leak-vulnerability)
- [ImageMagick stack buffer overflow in bzip2 decompression](https://junglewise.ai/threats/cve-2026-116149-imagemagick-before-6-9-13-58-and-7-x-before-7-1-2-33-contains-a)