Tom Lane discovered that PostgreSQL did not properly restrict
functions declared as "SECURITY DEFINER". An attacker could use this
to execute arbitrary SQL with the permissions of the function owner.
Andreas Seltenreich discovered that PostgreSQL did not properly handle
user-defined hash equality operators. An attacker could use this to
expose sensitive information (arbitrary PostgreSQL server memory). This
issue only affected Ubuntu 19.04. (CVE-2019-10209)
The problem can be corrected by updating your system to the following