Incompatible Change: The behavior of LOAD DATA INFILE and SELECT ... INTO OUTFILE has changed when the FIELDS TERMINATED BY and FIELDS ENCLOSED BY values both are empty. Formerly, a column was read or written the display width of the column. For example, INT(4) was read or written using a field with a width of 4. Now columns are read and written using a field width wide enough to hold all values in the field. However, data files written before this change was made might not be reloaded correctly with LOAD DATA INFILE for MySQL 4.1.12 and up. This change also affects data files read by mysqlimport and written by mysqldump --tab, which use LOAD DATA INFILE and SELECT ... INTO OUTFILE. For more information, see LOAD DATA INFILE Syntax. (Bug#12564)

Security Fix: Starting mysqld with --user=non_existent_user caused it to run using the privileges of the account from which it was invoked, including the root account. (Bug#9833)

Security Fix: mysql_install_db created the mysql_install_db.X file with a predictable filename and insecure permissions, which allowed local users to execute arbitrary SQL statements by modifying the file's contents. (CVE-2005-1636)