CVE-2026-78209
High
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.
SeverityHigh
CVSS8.2
Exploit probability—
ProductExceljs
PublishedAug 24, 2026
First seenAug 24, 2026
Weakness typeCWE-1236CWE-1236
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| exceljs exceljs | v ≤ 4.4.0 | — |
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