# ImageMagick: Heap Buffer Over-Write in MIFF encoder when using LZMA compression

Advisory record · `GHSA-jcqp-6r6f-3mfx`

- **Identifiers:** `GHSA-jcqp-6r6f-3mfx` · `CVE-2026-46521`
- **State:** Confirmed
- **Severity:** CVSS 5.5 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-131](https://cwe.mitre.org/data/definitions/131.html) · [CWE-252](https://cwe.mitre.org/data/definitions/252.html) · [CWE-787](https://cwe.mitre.org/data/definitions/787.html) · [CWE-835](https://cwe.mitre.org/data/definitions/835.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md) · [Denial of service](https://agentprime.io/advisories/tag/dos.md) · [CWE-252](https://agentprime.io/advisories/tag/cwe-252.md)
- **Published:** 18 May 2026
- **Updated:** 11 Jun 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 18 May 2026, 20:36 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `Magick.NET-Q16-AnyCPU` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-HDRI-AnyCPU` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-HDRI-OpenMP-arm64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-HDRI-OpenMP-x64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-HDRI-arm64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-HDRI-x64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-HDRI-x86` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-OpenMP-arm64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-OpenMP-x64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-arm64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-x64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q16-x86` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q8-AnyCPU` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q8-OpenMP-arm64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q8-OpenMP-x64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q8-arm64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q8-x64` (NuGet): affected `<14.13.1`; fixed in `14.13.1`
- `Magick.NET-Q8-x86` (NuGet): affected `<14.13.1`; fixed in `14.13.1`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.5 Medium, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0011, the 1st percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 15:22 UTC: First seen by agentprime
- 31 Oct 2026, 15:22 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-jcqp-6r6f-3mfx)

## Sources

- [GitHub Advisory Database: GHSA-jcqp-6r6f-3mfx](https://github.com/advisories/GHSA-jcqp-6r6f-3mfx)
- [OSV: GHSA-jcqp-6r6f-3mfx](https://osv.dev/vulnerability/GHSA-jcqp-6r6f-3mfx)
- <https://github.com/ImageMagick/ImageMagick/security/advisories/GHSA-jcqp-6r6f-3mfx>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-46521>
- <https://github.com/ImageMagick/ImageMagick>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-jcqp-6r6f-3mfx>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-jcqp-6r6f-3mfx/>. Everything for agents: <https://agentprime.io/llms.txt>.