How severe is CVE-2026-61866?

No CVSS score has been assigned to CVE-2026-61866 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-61866?

CVE-2026-61866 affects the following packages: Magick.NET-Q16-AnyCPU (NuGet), Magick.NET-Q16-HDRI-AnyCPU (NuGet), Magick.NET-Q16-HDRI-OpenMP-arm64 (NuGet), Magick.NET-Q16-HDRI-x64 (NuGet), Magick.NET-Q16-HDRI-x86 (NuGet), Magick.NET-Q16-OpenMP-arm64 (NuGet), Magick.NET-Q16-OpenMP-x64 (NuGet), Magick.NET-Q16-arm64 (NuGet), and 9 more. Ecosystems affected: NuGet.

How do I fix CVE-2026-61866?

Update Magick.NET-Q16-AnyCPU to 14.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-61866 is resolved across your whole dependency graph.

How do I detect CVE-2026-61866 in my NuGet dependencies?

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.

How do I mitigate CVE-2026-61866 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-61866 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-61866 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-61866?

CVE-2026-61866 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 8th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-61866?

CVE-2026-61866 is classified as CWE-401 (CWE-401). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-61866 published, and has it been updated?

CVE-2026-61866 was published on July 15, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

.NET NuGet

Not in CISA KEV

CVE-2026-61866 — Magick.NET-Q16-AnyCPU

CVE-2026-61866 is a CWE-401 vulnerability in Magick.NET-Q16-AnyCPU. A fix is available for Magick.NET-Q16-AnyCPU — see the affected versions and patch details below.

ImageMagick before 7.1.2-26 Memory Leak in JNG encoder

Also known asGHSA-99w9-hv66-rfv7

Published

Jul 15, 2026

Updated

Aug 12, 2026

Affected

17 pkgs

Patched

17 / 17

Exploits

None indexed

Exploitation data as of Oct 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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-2026-61866.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs8th percentile — riskier than 8% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

17 pkgs affected

.NETMagick.NET-Q16-AnyCPU.NETMagick.NET-Q16-HDRI-AnyCPU.NETMagick.NET-Q16-HDRI-OpenMP-arm64.NETMagick.NET-Q16-HDRI-x64.NETMagick.NET-Q16-HDRI-x86.NETMagick.NET-Q16-OpenMP-arm64.NETMagick.NET-Q16-OpenMP-x64.NETMagick.NET-Q16-arm64+9 more

Real-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

ImageMagick before 7.1.2-26 contains a memory leak vulnerability in the JNG encoder when a blob cannot be opened. Attackers can trigger the memory leak by providing malformed JNG files that fail blob operations, causing resource exhaustion.

Affected Packages

17 total 17 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`Magick.NET-Q16-AnyCPU`	all versions	14.15.0`dotnet add package Magick.NET-Q16-AnyCPU --version 14.15.0`
.NETNuGet	`Magick.NET-Q16-HDRI-AnyCPU`	all versions	14.15.0`dotnet add package Magick.NET-Q16-HDRI-AnyCPU --version 14.15.0`
.NETNuGet	`Magick.NET-Q16-HDRI-OpenMP-arm64`	all versions	14.15.0`dotnet add package Magick.NET-Q16-HDRI-OpenMP-arm64 --version 14.15.0`
.NETNuGet	`Magick.NET-Q16-HDRI-x64`	all versions	14.15.0`dotnet add package Magick.NET-Q16-HDRI-x64 --version 14.15.0`
.NETNuGet	`Magick.NET-Q16-HDRI-x86`	all versions	14.15.0`dotnet add package Magick.NET-Q16-HDRI-x86 --version 14.15.0`
.NETNuGet	`Magick.NET-Q16-OpenMP-arm64`	all versions	14.15.0`dotnet add package Magick.NET-Q16-OpenMP-arm64 --version 14.15.0`

Affected Products

1 product · 1 configurations

Application

imagemagickimagemagick

< 7.1.2-26

range

Detection & mitigation playbook

Open-source dependency

Detect
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 14.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-61866 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

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.

Red HatLow

Red Hat Enterprise Linux ships ImageMagick in RHEL 6 ELS and RHEL 7 ELS. This flaw has been rated as having a Low security impact and is not currently planned to be addressed in future updates of those products. For additional information, refer to the Issue Severity Classification:…

Workaround published by Red Hat

Do not process untrusted image files with ImageMagick. The JNG coder can be disabled in ImageMagick's policy.xml if not needed: `<policy domain="coder" rights="none" pattern="JNG"/>`. Upgrade to ImageMagick 7.1.2-26 or 6.9.13-51 mitigates the issue.

Source: Red Hat security advisory for CVE-2026-61866 (CC BY 4.0)

Frequently Asked Questions

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