CVE-2016-7262

CVE-2016-7262 is a security feature bypass in Microsoft Excel that allows arbitrary command execution when a crafted cell in a spreadsheet is mishandled upon a click. It is user-assisted: the victim must open a specially crafted workbook and interact with it, which matches the CVSS local attack vector and user-interaction requirement. Successful exploitation gives the attacker execution of arbitrary commands in the context of the logged-in user's privileges. Affected software spans Excel 2007 SP3, 2010 SP2, 2013 SP1, 2013 RT SP1, and 2016, as well as Office Compatibility Pack SP3 and Excel Viewer. The flaw is listed in CISA's Known Exploited Vulnerabilities catalog (added 2022-03-03), indicating known in-the-wild exploitation, and EPSS assigns a 57.9% probability of exploitation within 30 days.

What to do: Apply Microsoft's Office security updates across all affected Excel versions, per the CISA KEV required action (the fix shipped in Microsoft's December 2016 Office security bulletin MS16-148). Retire or upgrade away from Excel Viewer and Office Compatibility Pack, which are legacy components, and inventory endpoints for Excel 2007-2016 installs. As an interim mitigation, avoid clicking cells in untrusted or unsolicited spreadsheets and scan attachments before opening.