CVE-2018-10925
It was discovered that PostgreSQL versions before 10.5, 9.6.10, 9.5.14, 9.4.19, and 9.3.24 failed to properly check authorization on certain statements involved with "INSERT … ON CONFLICT DO UPDATE". An attacker with "CREATE TABLE" privileges could exploit this to read arbitrary bytes server memory. If the attacker also had certain "INSERT" and limited "UPDATE" privileges to a particular table, they could exploit this to update other columns in the same table.
Source: CVE-2018-10925