CVE-2026-78209
exceljs through 4.4.0 CSV Formula Injection via Unescaped Cell Values
- State
- Published
- Severity
- 8.4 High
- Published
- Aug 24, 2026
- Updated
- Aug 29, 2026
- Reserved
- Aug 24, 2026
Description
exceljs through 4.4.0 fails to neutralize leading equals, plus, minus, or at signs in cell values written to CSV output. Attackers who can influence exported cell values can inject formulas that execute when the CSV file is opened in a spreadsheet application, potentially exfiltrating data or performing other malicious actions.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.4 High | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N | VulnCheck |
| 3.1 | 8.2 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N | VulnCheck |
Weaknesses
- CWE-1236 Improper Neutralization of Formula Elements in a CSV File
Affected Products
| Product | Versions |
|---|---|
exceljsexceljs |
|
References
- https://github.com/exceljs/exceljsproduct
- GitHub Security Advisory (GHSA-9wxc-4rhw-hfrw)third-party-advisory
- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/csv/csv.js#L109-L182technical-description
- VulnCheck Advisory: exceljs through 4.4.0 CSV Formula Injection via Unescaped Cell Valuesthird-party-advisory
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