Spreadsheet formula injection in conversion-tracking report exports in Revive Adserver 6.0.8 and earlier allows an unauthenticated attacker to submit conversion values that are written as formulas instead of text in an XLS workbook. When a user opens the exported report in a spreadsheet application, attacker-supplied formulas can be evaluated. The confirmed impact is formula execution within the workbook; disclosure of information to the attacker has not been established. The issue is fixed in Revive Adserver 6.0.9 by sanitising conversion values before writing them to the affected XLS report sections.