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
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-25794 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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 |
Detection & 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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-25794 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-25794. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
Frequently Asked Questions
Is CVE-2026-25794 in your dependencies?
O3 Security finds CVE-2026-25794 across NuGet dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.