pg_partman is a PostgreSQL extension that manages partitioned tables by time or ID. Prior to 5.5.0, when pg_jobmon is installed and part_config.jobmon is true, exception handlers in multiple pg_partman functions place p_parent_table verbatim inside a SQL string literal used to call pg_jobmon.add_job(). A partman_user can create a parent-table name containing a single quote that terminates the literal and injects SQL when an affected exception path runs. If pg_partman_bgw reaches that path, the injected SQL executes with pg_partman_bgw.role privileges, which default to PostgreSQL superuser, permitting database-wide compromise and operating-system command execution as the PostgreSQL service account. The persistent part_config row can trigger the escalation again on later maintenance ticks. This issue is fixed in version 5.5.0.
https://github.com/pgpartman/pg_partman/security/advisories/GHSA-gv5h-j2cm-rhc3
https://github.com/pgpartman/pg_partman/releases/tag/v5.5.0
https://github.com/pgpartman/pg_partman/commit/ba9405542acf24dd881845b935cab8b165854361