Security Fix: For servers built with yaSSL, a preauthorization buffer overflow could cause memory corruption or a server crash. We thank Evgeny Legerov from Intevydis for providing us with a proof-of-concept script that allowed us to reproduce this bug. (Bug#50227, CVE-2009-4484)

Incompatible Change: In plugin.h, the MYSQL_REPLICATION_PLUGIN symbol was out of synchrony with its value in MySQL 6.0 because the lower-valued MYSQL_AUDIT_PLUGIN was not present. To correct this, MYSQL_AUDIT_PLUGIN has been added in MySQL 5.5, changing the value of MYSQL_REPLICATION_PLUGIN from 5 to 6. Attempts to load the audit plugin produce an error occurs because only the MYSQL_AUDIT_PLUGIN symbol was added, not the audit plugin itself. This error will go away when the audit plugin is added to MySQL 5.5 (in 5.5.3). Replication plugins from earlier 5.5.x releases must be recompiled against the current release before they will work with the current release. (Bug#49894)