pg_partman is a PostgreSQL extension that manages partitioned tables by time or ID. Prior to 5.5.0, run_maintenance() handles exceptions outside the loop that processes rows from part_config, so an exception for one partition set immediately terminates the loop and skips every later set. A role with partman_user access can insert or update a row that reliably fails and assign it a low maintenance_order value so it is processed before legitimate rows. Repeated maintenance ticks then abort before legitimate partition sets are maintained, causing database-wide loss of automated partition maintenance. This issue is fixed in version 5.5.0.
https://github.com/pgpartman/pg_partman/security/advisories/GHSA-9m6c-hw23-c6h2
https://github.com/pgpartman/pg_partman/releases/tag/v5.5.0
https://github.com/pgpartman/pg_partman/commit/ba9405542acf24dd881845b935cab8b165854361