A format string vulnerability exists in PostgreSQL's pg_basebackup utility that allows an attacker with prior server compromise to potentially disclose memory contents from the backup manifest. The vulnerability does not leak data directly to the attacker, requiring additional secrets to exploit. Integrity impact is unlikely as the formatter does not support %n. Versions before PostgreSQL 18.7, 17.12, 16.16, 15.20, and 14.25 are affected.