In ImageMagick 7.x before 7.0.8-42 and 6.x before 6.9.10-42, there is a use after free vulnerability in the UnmapBlob function that allows an attacker to cause a denial of service by sending a crafted file.
Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:NI:NA:H6.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H