# PostgreSQL superuser privileges pose significant security risks

> **Key takeaway:** Application roles should avoid superuser status because it grants host-level shell access and file system control.

**Published:** 2026-10-22T16:29:10+00:00 
**Source:** Planet PostgreSQL 
**Category:** databases-storage 
**Canonical URL:** https://fosswire.org/news/postgresql-superuser-privileges-pose-significant-security-ri.html 

## Summary
A technical guide by Umair Shahid explains why granting superuser privileges to applications is dangerous. A superuser can bypass all database permissions, execute shell commands via COPY ... PROGRAM, and read or write files directly on the server. The article provides safer alternatives, such as using dedicated schemas and built-in roles like pg_read_all_data.

## Risks and safer alternatives in PostgreSQL
- **Superuser capabilities**: Can bypass all permission checks, disable row-level security, and use `ALTER SYSTEM` to change server configuration.
- **Host access**: Can execute shell commands using `COPY ... PROGRAM` and run arbitrary code via untrusted languages like `plpython3u` or `plperlu`.
- **File system access**: Can read and write files on the server using `pg_read_file` and `pg_write_file`.
- **Mitigation via schemas**: Assigning a dedicated schema to a role via `CREATE SCHEMA ... AUTHORIZATION` allows object management without global rights.
- **Granular roles**: Use `pg_read_all_data` or `pg_write_all_data` (introduced in Postgres 14) instead of superuser for broad data access.
- **Restricted privileges**: Avoid granting `CREATEROLE`, `CREATEDB`, or server-file roles like `pg_execute_server_program` to application accounts.

## Why it matters
Encourages better security practices for database administrators and developers to prevent database leaks from escalating into full server compromises.