ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to versions 6.9.13-51 and 7.1.2-26, the MNG decoder contains a possible heap information disclosure vulnerability because part of the pixels are left unchanged. This issue has been fixed in versions 6.9.13-51 and 7.1.2-26.
https://github.com/ImageMagick/ImageMagick/security/advisories/GHSA-8g53-9m3c-69xg