CVE-2021-32040

It may be possible to have an extremely long aggregation pipeline in conjunction with a specific stage/operator and cause a stack overflow due to the size of the stack frames used by that stage. If an attacker could cause such an aggregation to occur, they could maliciously crash MongoDB in a DoS attack. This vulnerability affects MongoDB versions prior to 5.0.4, 4.4.11, 4.2.16.

Source: CVE-2021-32040