CVE-2026-25794 is a high-severity (CVSS 8.2) CWE-122 vulnerability in Magick.NET-Q16-AnyCPU. A fix is available for Magick.NET-Q16-AnyCPU — see the affected versions and patch details below.
ImageMagick has heap-buffer-overflow via signed integer overflow in `WriteUHDRImage` when writing UHDR images with large dimensions
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-25794.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
Magick.NET-Q16-AnyCPU.NETMagick.NET-Q16-HDRI-AnyCPU.NETMagick.NET-Q16-HDRI-OpenMP-arm64.NETMagick.NET-Q16-HDRI-OpenMP-x64.NETMagick.NET-Q16-HDRI-arm64.NETMagick.NET-Q16-HDRI-x64.NETMagick.NET-Q16-HDRI-x86.NETMagick.NET-Q16-OpenMP-arm64+11 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
WriteUHDRImage in coders/uhdr.c uses int arithmetic to compute the pixel buffer size. When image dimensions are large, the multiplication overflows 32-bit int, causing an undersized heap allocation followed by an out-of-bounds write. This can crash the process or potentially lead to an out of bounds heap write.
==1575126==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7fc382ef3820 at pc 0x5560d31f229f bp 0x7ffe865f9530 sp 0x7ffe865f9520
WRITE of size 8 at 0x7fc382ef3820 thread T0
#0 0x5560d31f229e in WriteUHDRImage coders/uhdr.c:807
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Magick.NET-Q16-AnyCPU | all versions | 14.10.3dotnet add package Magick.NET-Q16-AnyCPU --version 14.10.3 |
| .NETNuGet | Magick.NET-Q16-HDRI-AnyCPU | all versions | 14.10.3dotnet add package Magick.NET-Q16-HDRI-AnyCPU --version 14.10.3 |
| .NETNuGet | Magick.NET-Q16-HDRI-OpenMP-arm64 | all versions | 14.10.3dotnet add package Magick.NET-Q16-HDRI-OpenMP-arm64 --version 14.10.3 |
| .NETNuGet | Magick.NET-Q16-HDRI-OpenMP-x64 | all versions | 14.10.3dotnet add package Magick.NET-Q16-HDRI-OpenMP-x64 --version 14.10.3 |
| .NETNuGet | Magick.NET-Q16-HDRI-arm64 | all versions | 14.10.3dotnet add package Magick.NET-Q16-HDRI-arm64 --version 14.10.3 |
| .NETNuGet | Magick.NET-Q16-HDRI-x64 | all versions | 14.10.3dotnet add package Magick.NET-Q16-HDRI-x64 --version 14.10.3 |
Affected Products
imagemagickimagemagickDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Magick.NET-Q16-AnyCPU, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update Magick.NET-Q16-AnyCPU to 14.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-25794 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This IMPORTANT heap-buffer-overflow vulnerability in ImageMagick's `WriteUHDRImage` function can lead to a denial of service or potentially arbitrary code execution when processing specially crafted UHDR images with excessively large dimensions. Red Hat Enterprise Linux 6 ELS and 7 ELS are affected by this flaw, which…
To mitigate this vulnerability, avoid processing untrusted or maliciously crafted UHDR image files with ImageMagick. Limiting the exposure of ImageMagick to untrusted input can reduce the risk of exploitation.Source: Red Hat security advisory for CVE-2026-25794 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-25794 in your dependencies?
Find it across NuGet, including transitive dependencies.