CVE-2026-78209
CVE-2026-78209
exceljs-hardened versions before 5.0.0 fail 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.
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N.
Weakness classification (CWE)
References
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (third-party-advisory)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-78209?
- CVE-2026-78209 is a high-severity vulnerability, classified under Improper Neutralization of Formula Elements in a CSV File. CVSS score: 8.2/10. Published 2026-08-24.
- How severe is CVE-2026-78209?
- High severity. CVSS v3 base score is 8.2 out of 10.