Steffen Joeris discovered that PyGreSQL 3.8 did not use PostgreSQL"s safe string and bytea functions in its own escaping functions. As a result, applications written to use PyGreSQL"s escaping functions are vulnerable to SQL injections when processing certain multi-byte character sequences. Because the safe functions require a database connection, to maintain backwards compatibility, pg.escape_string and pg.escape_bytea are still available, but applications will have to be adjusted to use the new pyobj.escape_string and pyobj.escape_bytea functions. For example, code containing: import pg connection = pg.connect escaped = pg.escape_string should be adjusted to use: import pg connection = pg.connect escaped = connection.escape_string