source: http://www.securityfocus.com/bid/15926/info

Microsoft Excel is susceptible to two unspecified memory-corruption vulnerabilities. The issues present themselves when Microsoft Excel tries to process malformed or corrupted XLS files.

Attackers may exploit these issues to crash the affected application and possibly to execute arbitrary machine code.

This BID will be updated and potentially split into separate records as further information is disclosed.

UPDATE (Mar 14, 2006): Microsoft has released security advisory MS06-012 addressing this and other issues.

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/bin-sploits/26869-1.xls

https://github.com/offensive-security/exploit-database-bin-sploits/raw/master/bin-sploits/26869-2.xls