MS10-057  Vulnerability in Microsoft Office Excel Could Allow Remote Code Execution (2269707)

Important - Remote Code Execution This security update resolves a privately reported vulnerability in Microsoft Office. The vulnerability could allow remote code execution if a user opens a specially crafted Excel file. An attacker who successfully exploited this vulnerability could gain the same user rights as the logged-on user. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.
Bulletin details at Microsoft.com