In PostgreSQL, versions 9.5 prior to REL9_5_20, 9.6 prior to REL9_6_16, 10 prior to REL_10_11, 11 prior to REL_11_6, 12 prior to REL_12_1, are vulnerable to uncontrolled resource consumption, due to a missing if maximum child processes are running when creating a new bgworker. When the postmaster’s child-process arrays are temporarily full, a malicious client can spawn a new bgworker process and crash the postmaster.