CVE-2026-46521: ImageMagick Heap Buffer Over-Write Vulnerability

MODERATE
Advisory Identifier: GHSA-jcqp-6r6f-3mfx
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CVSS 5.5
CWE-252 CWE-787 CWE-835 CWE-131
Published
Advisory Summary

CVE-2026-46521 is a MODERATE (CVSS 5.5) heap buffer over-write vulnerability (CWE-252: Unchecked Return Value) affecting ImageMagick libraries in the NuGet ecosystem. The issue involves heap buffer over-write in miff encoder when using lzma compression. Remediation is available by upgrading affected packages to version 14.13.1.

CVE-2026-46521 at a Glance

CVE Identifier CVE-2026-46521
GHSA Identifier GHSA-jcqp-6r6f-3mfx
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-252: Unchecked Return Value
Affected Product ImageMagick
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 5.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-46521

To remediate this vulnerability, upgrade all affected ImageMagick dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Magick.NET-Q16-AnyCPU fixed: 14.13.1 
Upgrade Magick.NET-Q16-AnyCPU to 14.13.1
Magick.NET-Q16-HDRI-AnyCPU fixed: 14.13.1 
Upgrade Magick.NET-Q16-HDRI-AnyCPU to 14.13.1
Magick.NET-Q16-HDRI-OpenMP-arm64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-HDRI-OpenMP-arm64 to 14.13.1
Magick.NET-Q16-HDRI-OpenMP-x64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-HDRI-OpenMP-x64 to 14.13.1
Magick.NET-Q16-HDRI-arm64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-HDRI-arm64 to 14.13.1
Magick.NET-Q16-HDRI-x64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-HDRI-x64 to 14.13.1
Magick.NET-Q16-HDRI-x86 fixed: 14.13.1 
Upgrade Magick.NET-Q16-HDRI-x86 to 14.13.1
Magick.NET-Q16-OpenMP-arm64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-OpenMP-arm64 to 14.13.1
Magick.NET-Q16-OpenMP-x64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-OpenMP-x64 to 14.13.1
Magick.NET-Q16-arm64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-arm64 to 14.13.1
Magick.NET-Q16-x64 fixed: 14.13.1 
Upgrade Magick.NET-Q16-x64 to 14.13.1
Magick.NET-Q16-x86 fixed: 14.13.1 
Upgrade Magick.NET-Q16-x86 to 14.13.1
Magick.NET-Q8-AnyCPU fixed: 14.13.1 
Upgrade Magick.NET-Q8-AnyCPU to 14.13.1
Magick.NET-Q8-OpenMP-arm64 fixed: 14.13.1 
Upgrade Magick.NET-Q8-OpenMP-arm64 to 14.13.1
Magick.NET-Q8-OpenMP-x64 fixed: 14.13.1 
Upgrade Magick.NET-Q8-OpenMP-x64 to 14.13.1
Magick.NET-Q8-arm64 fixed: 14.13.1 
Upgrade Magick.NET-Q8-arm64 to 14.13.1
Magick.NET-Q8-x64 fixed: 14.13.1 
Upgrade Magick.NET-Q8-x64 to 14.13.1
Magick.NET-Q8-x86 fixed: 14.13.1 
Upgrade Magick.NET-Q8-x86 to 14.13.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for Magick.NET-Q16-AnyCPU

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-46521, inspect your project dependencies for ImageMagick:

inspect dependencies for Magick.NET-Q16-AnyCPU

Analyze the terminal output to locate any version of ImageMagick in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 14.13.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-252: Unchecked Return Value, where the product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions. In ImageMagick, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

When using LZMA compression in the MIFF encoder an out of bounds write can occur due to a missing check.

CVE-2026-46521 Affected ImageMagick Versions

18 component(s)
Fixed Versions:
14.13.1
Product / Package Ecosystem Affected Versions Fixed Version
Magick.NET-Q16-AnyCPU
nuget/Magick.NET-Q16-AnyCPU
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-HDRI-AnyCPU
nuget/Magick.NET-Q16-HDRI-AnyCPU
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-HDRI-OpenMP-arm64
nuget/Magick.NET-Q16-HDRI-OpenMP-arm64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-HDRI-OpenMP-x64
nuget/Magick.NET-Q16-HDRI-OpenMP-x64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-HDRI-arm64
nuget/Magick.NET-Q16-HDRI-arm64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-HDRI-x64
nuget/Magick.NET-Q16-HDRI-x64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-HDRI-x86
nuget/Magick.NET-Q16-HDRI-x86
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-OpenMP-arm64
nuget/Magick.NET-Q16-OpenMP-arm64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-OpenMP-x64
nuget/Magick.NET-Q16-OpenMP-x64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-arm64
nuget/Magick.NET-Q16-arm64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-x64
nuget/Magick.NET-Q16-x64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q16-x86
nuget/Magick.NET-Q16-x86
NuGet
< 14.13.1
14.13.1
Magick.NET-Q8-AnyCPU
nuget/Magick.NET-Q8-AnyCPU
NuGet
< 14.13.1
14.13.1
Magick.NET-Q8-OpenMP-arm64
nuget/Magick.NET-Q8-OpenMP-arm64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q8-OpenMP-x64
nuget/Magick.NET-Q8-OpenMP-x64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q8-arm64
nuget/Magick.NET-Q8-arm64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q8-x64
nuget/Magick.NET-Q8-x64
NuGet
< 14.13.1
14.13.1
Magick.NET-Q8-x86
nuget/Magick.NET-Q8-x86
NuGet
< 14.13.1
14.13.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/ImageMagick/ImageMagick/security/advisories/GHSA-jcqp-6r6f-3mfx
NVD — CVE-2026-46521 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-46521
ImageMagick Source Repository REPOSITORY
https://github.com/ImageMagick/ImageMagick

Frequently Asked Questions

What is CVE-2026-46521?
CVE-2026-46521 is a security vulnerability in ImageMagick involving Heap Buffer Over-Write in MIFF encoder when using LZMA compression under CWE-252: Unchecked Return Value.
Which ImageMagick versions are affected?
Affected versions include releases prior to 14.13.1 across affected packages: Magick.NET-Q16-AnyCPU, Magick.NET-Q16-HDRI-AnyCPU, Magick.NET-Q16-HDRI-OpenMP-arm64, Magick.NET-Q16-HDRI-OpenMP-x64, Magick.NET-Q16-HDRI-arm64, Magick.NET-Q16-HDRI-x64, Magick.NET-Q16-HDRI-x86, Magick.NET-Q16-OpenMP-arm64, Magick.NET-Q16-OpenMP-x64, Magick.NET-Q16-arm64, Magick.NET-Q16-x64, Magick.NET-Q16-x86, Magick.NET-Q8-AnyCPU, Magick.NET-Q8-OpenMP-arm64, Magick.NET-Q8-OpenMP-x64, Magick.NET-Q8-arm64, Magick.NET-Q8-x64, Magick.NET-Q8-x86.
What version fixes CVE-2026-46521?
Upgrading to 14.13.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Magick.NET-Q16-AnyCPU affected?
Yes, Magick.NET-Q16-AnyCPU is affected in releases prior to 14.13.1. Upgrade your dependency to 14.13.1 or later.
Is Magick.NET-Q16-HDRI-AnyCPU affected?
Yes, Magick.NET-Q16-HDRI-AnyCPU is affected in releases prior to 14.13.1. Upgrade your dependency to 14.13.1 or later.
What is the CVSS score of CVE-2026-46521?
CVE-2026-46521 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-46521?
CVE-2026-46521 is classified under CWE-252: Unchecked Return Value (The product does not check the return value from a method or function, which can prevent it from detecting unexpected states and conditions.).
How can I check NuGet dependencies for CVE-2026-46521?
Run the dependency tree command: 'inspect dependencies for Magick.NET-Q16-AnyCPU'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-jcqp-6r6f-3mfx",
  "modified" : "2026-06-11T14:05:56Z",
  "published" : "2026-05-18T20:36:53Z",
  "aliases" : [ "CVE-2026-46521" ],
  "summary" : "ImageMagick: Heap Buffer Over-Write in MIFF encoder when using LZMA compression",
  "details" : "When using LZMA compression in the MIFF encoder an out of bounds write can occur due to a missing check.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-AnyCPU"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-HDRI-AnyCPU"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
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      }, {
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      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-HDRI-OpenMP-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
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      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-HDRI-OpenMP-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
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    },
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  }, {
    "package" : {
      "ecosystem" : "NuGet",
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    },
    "ranges" : [ {
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      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-HDRI-x86"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-OpenMP-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-OpenMP-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-x64"
    },
    "ranges" : [ {
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      "events" : [ {
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  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q16-x86"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q8-AnyCPU"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
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    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q8-OpenMP-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q8-OpenMP-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q8-arm64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q8-x64"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Magick.NET-Q8-x86"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "14.13.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/ImageMagick/ImageMagick/security/advisories/GHSA-jcqp-6r6f-3mfx"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-46521"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ImageMagick/ImageMagick"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-131", "CWE-252", "CWE-787", "CWE-835" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-18T20:36:53Z",
    "nvd_published_at" : "2026-06-10T23:16:46Z"
  }
}