There is an invalid free in the MagickFree function in magick/memory.c in GraphicsMagick 1.3.26 that will lead to a remote denial of service attack.
Exploitability
AV:NAC:LPR:NUI:RScope
S:UImpact
C:NI:NA:H6.5/CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H