The application's list box calculate array logic keeps stale references to page or form objects after they are deleted or re-created, which allows crafted documents to trigger a use-after-free when the calculation runs and can potentially lead to arbitrary code execution.
Exploitability
AV:LAC:LPR:NUI:RScope
S:UImpact
C:HI:HA:H7.8/CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HMemory Safety