The convert_search_mode_to_innobase function in ha_innodb.cc in the InnoDB engine in MySQL 5.1.23-BK and earlier allows remote authenticated users to cause a denial of service (database crash) via a certain CONTAINS operation on an indexed column, which triggers an assertion error.

More... (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-5925)