Client use of server error message in PostgreSQL allows a server not trusted under current SSL or GSS settings to furnish arbitrary non-NUL bytes to the libpq application. For example, a man-in-the-middle attacker could send a long error message that a human or screen-scraper user of psql mistakes for valid query results. This is probably not a concern for clients where the user interface unambiguously indicates the boundary between one error message and other text. Versions before PostgreSQL 17.1, 16.5, 15.9, 14.14, 13.17, and 12.21 are affected.