CVE-2026-33899: ImageMagick heap buffer overflow in XML parsing

Quick answers

Is CVE-2026-33899 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-33899 being exploited in the wild.

How severe is CVE-2026-33899?

Medium severity, with a CVSS score of 5.3, published 13 April 2026.

Which products and versions are affected?

Magick.NET-Q16-AnyCPU (NuGet) < 14.12.0, ECOSYSTEM:introduced=0,fixed=14.12.0; Magick.NET-Q16-arm64 (NuGet) < 14.12.0, ECOSYSTEM:introduced=0,fixed=14.12.0; Magick.NET-Q16-HDRI-AnyCPU (NuGet) < 14.12.0, ECOSYSTEM:introduced=0,fixed=14.12.0; Magick.NET-Q16-HDRI-arm64 (NuGet) < 14.12.0, ECOSYSTEM:introduced=0,fixed=14.12.0; and 13 more.

Is there a fix for CVE-2026-33899?

Yes. Magick.NET-Q16-AnyCPU (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-arm64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-HDRI-AnyCPU (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-HDRI-arm64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-HDRI-OpenMP-arm64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-HDRI-x64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-HDRI-x86 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-OpenMP-arm64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-OpenMP-x64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-x64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q16-x86 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q8-AnyCPU (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q8-arm64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q8-OpenMP-arm64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q8-OpenMP-x64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q8-x64 (NuGet): upgrade to 14.12.0 or later; Magick.NET-Q8-x86 (NuGet): upgrade to 14.12.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-33899 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-33899?

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.

How to fix

• Magick.NET-Q16-AnyCPU (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-AnyCPU --version 14.12.0

• Magick.NET-Q16-arm64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-arm64 --version 14.12.0

• Magick.NET-Q16-HDRI-AnyCPU (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-HDRI-AnyCPU --version 14.12.0

• Magick.NET-Q16-HDRI-arm64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-HDRI-arm64 --version 14.12.0

• Magick.NET-Q16-HDRI-OpenMP-arm64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-HDRI-OpenMP-arm64 --version 14.12.0

• Magick.NET-Q16-HDRI-x64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-HDRI-x64 --version 14.12.0

• Magick.NET-Q16-HDRI-x86 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-HDRI-x86 --version 14.12.0

• Magick.NET-Q16-OpenMP-arm64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-OpenMP-arm64 --version 14.12.0

• Magick.NET-Q16-OpenMP-x64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-OpenMP-x64 --version 14.12.0

• Magick.NET-Q16-x64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-x64 --version 14.12.0

• Magick.NET-Q16-x86 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q16-x86 --version 14.12.0

• Magick.NET-Q8-AnyCPU (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q8-AnyCPU --version 14.12.0

• Magick.NET-Q8-arm64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q8-arm64 --version 14.12.0

• Magick.NET-Q8-OpenMP-arm64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q8-OpenMP-arm64 --version 14.12.0

• Magick.NET-Q8-OpenMP-x64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q8-OpenMP-x64 --version 14.12.0

• Magick.NET-Q8-x64 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q8-x64 --version 14.12.0

• Magick.NET-Q8-x86 (NuGet): upgrade to 14.12.0 or later

  dotnet add package Magick.NET-Q8-x86 --version 14.12.0

Technical details

A heap-based buffer overflow (CWE-122) and integer underflow (CWE-191) exist in ImageMagick's XML parsing logic. When processing a malformed XML file, the application may perform an out-of-bounds write of a single zero byte. This vulnerability can be triggered remotely without authentication or user interaction if the application processes untrusted XML input. An attacker could potentially cause a denial-of-service (DoS) condition. The issue is addressed in ImageMagick version 7.1.2-19 and Magick.NET version 14.12.0.

Affected products

• ImageMagick ImageMagick < 7.1.2-19
• dlemstra Magick.NET < 14.12.0

Identifiers

• CVE-2026-33899
• GHSA-cr67-pvmx-2pp2

Timeline

• 2026-04-13: disclosed
• 2026-04-13: advisory
• 2026-04-13: patched: Fixed in ImageMagick 7.1.2-19 and Magick.NET 14.12.0

References

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