CVE-2026-78209
exceljs through 4.4.0 CSV Formula Injection via Unescaped Cell Values
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| exceljs exceljs exceljs
npm |
≥ 0; ≤ 4.4.0 (affected, semver)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 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 | CNA: 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 | CNA: VulnCheck |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/exceljs/exceljsCNA: VulnCheck · product
- https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-9wxc-4rhw-hfrwCNA: VulnCheck · third-party-advisory, vendor-advisory
- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/csv/csv.js#L109-L182CNA: VulnCheck · technical-description
- https://www.vulncheck.com/advisories/exceljs-through-csv-formula-injection-via-unescaped-cell-valuesCNA: VulnCheck · third-party-advisory
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