Executive brief
The MongoSQL Transition Readiness Tool, a utility used to assess migration readiness for MongoDB databases, generates CSV reports that fail to sanitize database and collection names. An attacker with write access to the cluster can create databases or collections with names starting with formula characters (such as "="). When an operator opens the generated report in Excel, Google Sheets, or other spreadsheet software, these names are interpreted as formulas, potentially exposing sensitive report data or causing malicious code execution on the operator's workstation.
Technical details
This vulnerability is a CSV formula injection (also known as CSV injection or spreadsheet formula injection) in the report generation functionality. The root cause is insufficient output encoding: database and collection names are written directly into CSV files without escaping or neutralizing leading characters that spreadsheet applications treat as formula delimiters (=, +, -, @, etc.). An authenticated attacker with cluster write privileges can create a malicious namespace (database.collection pair) with a name beginning with "=" or similar characters; when the report is generated and opened in a spreadsheet application, the malicious formula is executed. The attack requires the operator to open the generated report file in a spreadsheet application. The fix involves properly escaping or prefixing user-controlled data in CSV output to prevent formula interpretation.
Affected products
- MongoDB MongoSQL Transition Readiness Tool
Timeline
- 2026-08-28: disclosed