A vulnerability was found in postgresql versions 11.x prior to 11.3. The Windows installer for EnterpriseDB-supplied PostgreSQL does not lock down the ACL of the binary installation directory or the ACL of the data directory; it keeps the inherited ACL. In the default configuration, this allows a local attacker to read arbitrary data directory files, essentially bypassing database-imposed read access limitations. In plausible non-default configurations, an attacker having both an unprivileged Windows account and an unprivileged PostgreSQL account can cause the PostgreSQL service account to execute arbitrary code.
https://www.postgresql.org/about/news/1939/