CVE-2026-40183 ImageMagick: Heap buffer overflow when encoding JXL image with a 16-bit float

What is CVE-2026-40183?

CVE-2026-40183 is a medium-severity memory corruption vulnerability in Imagemagick Imagemagick, published on 13 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

ImageMagick is free and open-source software used for editing and manipulating digital images. In versions below 7.1.2-19, the JXL encoder has an heap write overflow when a user specifies that the image should be encoded as 16 bit floats. This issue has been fixed in version 7.1.2-19.

Weakness: CWE-122

Which versions are affected by CVE-2026-40183?

34 open source packages ship an affected version, including Magick.NET-Q16-AnyCPU, Magick.NET-Q16-HDRI-AnyCPU and Magick.NET-Q16-HDRI-OpenMP-arm64. It affects 1 product.

Products include Imagemagick Imagemagick.

How do I fix CVE-2026-40183?

Upgrade Magick.NET-Q16-AnyCPU to 14.12.0 or later.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2026-40183 being exploited?

There is no known exploitation of CVE-2026-40183 in the wild and no public exploit code.

Other vulnerabilities in Imagemagick Imagemagick

• CVE-2019-19952 Use after free in n/a Critical 9.8
• CVE-2018-16328 Null dereference in n/a Critical 9.8
• CVE-2018-16329 Null dereference in n/a Critical 9.8
• CVE-2017-18210 Null dereference in n/a Critical 9.8
• CVE-2017-14138 Denial of service in n/a Critical 9.8

All Imagemagick Imagemagick vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2026-40183, GHSA-jvgr-9ph5-m8v4, JLSEC-2026-1001, MINI-jh3j-qrhg-76vm, UBUNTU-CVE-2026-40183.