ImageMagick CLAHE : Unsigned underflow and division-by-zero lead to OOB pointer arithmetic and process crash (DoS)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.7 · CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS

• CVE-2025-62594: 0.37% estimated exploitation activity in the next 30 days; percentile 30.84 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A single root cause in the CLAHE implementation — tile width/height becoming zero — produces two distinct but related unsafe behaviors. Vulnerabilities exists in the CLAHEImage() function of ImageMagick’s MagickCore/enhance.c. 1. Unsigned integer underflow → out-of-bounds pointer arithmetic (OOB): when tileinfo.height == 0, the expression tileinfo.height - 1 (unsigned) wraps to a very large value; using that value in pointer arithmetic yields a huge offset and OOB memory access (leading to memory corruption, SIGSEGV, or resource exhaustion). 2. Division/modulus by zero: where code performs ... / tileinfo.width or ... % tileinfo.height without re-checking for zero, causing immediate division-by-zero crashes under sanitizers or abort at runtime. Both behaviors are triggered by the same invalid tile condition (e.g., CLI exact -clahe 0x0! or automatic tile derivation dim 3 == 0 for very small images). --- Details Unsigned underflow(can lea to OOB) - Location:…

Published by the source

27 Oct 2025, 23:33 UTC

Last modified by the source

31 Oct 2025, 09:29 UTC

Source last checked

26 Oct 2026, 17:04 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wpp4-vqfq-v4hp

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# Patch Next advisory brief: CVE-2025-62594

Advisory: ImageMagick CLAHE : Unsigned underflow and division-by-zero lead to OOB pointer arithmetic and process crash (DoS)
IDs: CVE-2025-62594, GHSA-wpp4-vqfq-v4hp
Record: https://patchnext.com/advisories/cve-2025-62594 (revision 1, source checked 26 Oct 2026, 17:04 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- NuGet magick.net-q8-arm64: affected <= 14.9.0
- NuGet magick.net-q16-openmp-x64: affected <= 14.9.0
- NuGet magick.net-q16-hdri-openmp-arm64: affected <= 14.9.0
- NuGet magick.net-q16-hdri-arm64: affected <= 14.9.0
- NuGet magick.net-q8-openmp-x64: affected <= 14.9.0
- NuGet magick.net-q16-hdri-openmp-x64: affected <= 14.9.0
- NuGet magick.net-q16-openmp-arm64: affected <= 14.9.0
- NuGet magick.net-q16-x64: affected <= 14.9.0
- NuGet magick.net-q8-x64: affected <= 14.9.0
- NuGet magick.net-q8-openmp-arm64: affected <= 14.9.0
- NuGet magick.net-q16-arm64: affected <= 14.9.0
- NuGet magick.net-q16-hdri-x64: affected <= 14.9.0

## Suggested inspection (read-only)
- NuGet magick.net-q8-arm64: check the installed version with your package manager.
- NuGet magick.net-q16-openmp-x64: check the installed version with your package manager.
- NuGet magick.net-q16-hdri-openmp-arm64: check the installed version with your package manager.
- NuGet magick.net-q16-hdri-arm64: check the installed version with your package manager.
- NuGet magick.net-q8-openmp-x64: check the installed version with your package manager.
- NuGet magick.net-q16-hdri-openmp-x64: check the installed version with your package manager.
- NuGet magick.net-q16-openmp-arm64: check the installed version with your package manager.
- NuGet magick.net-q16-x64: check the installed version with your package manager.
- NuGet magick.net-q8-x64: check the installed version with your package manager.
- NuGet magick.net-q8-openmp-arm64: check the installed version with your package manager.
- NuGet magick.net-q16-arm64: check the installed version with your package manager.
- NuGet magick.net-q16-hdri-x64: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on magick.net-q8-arm64, magick.net-q16-openmp-x64, magick.net-q16-hdri-openmp-arm64, magick.net-q16-hdri-arm64, magick.net-q8-openmp-x64, magick.net-q16-hdri-openmp-x64, magick.net-q16-openmp-arm64, magick.net-q16-x64, magick.net-q8-x64, magick.net-q8-openmp-arm64, magick.net-q16-arm64, magick.net-q16-hdri-x64.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wpp4-vqfq-v4hp (GitHub-reviewed advisory GHSA-wpp4-vqfq-v4hp lists affected ranges: NuGet magick.net-q16-x64 >=0 =0 =0 =0 =0 =0 =0 =0 =0 =0…)

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