Matrix Media Repo (MMR) allows untrusted file formats can be thumbnailed, invoking potentially further untrusted decoders

Impact If SVG or JPEGXL thumbnailers are enabled they are disabled by default, a user may upload a file which claims to be either of these types and request a thumbnail to invoke a different decoder in ImageMagick. In some ImageMagick installations, this includes the capability to run Ghostscript...