A specially crafted aggregation query with $lookup by an authenticated user with write privileges can cause a double-free or use-after-free memory issue in the slot-based execution (SBE) engine when an in-memory hash table is spilled to disk.
Exploitability
AV:NAC:HAT:NPR:LUI:NVulnerable System
VC:LVI:LVA:HSubsequent System
SC:NSI:NSA:N6.1/CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:NOther