Vulnerability record/PUBLISHED/Published Aug 24, 2026 00:30:48 UTC

CVE-2026-78209

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.

Base score8.4/ 10

SeverityHighCVSS 4.0

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityHigh

Attack vectorNetworkAV

Attack complexityLowAC

Attack requirementsNoneAT

Privileges requiredNonePR

User interactionPassiveUI

Vulnerable system confidentialityHighVC

Vulnerable system integrityLowVI

Vulnerable system availabilityNoneVA

Subsequent system confidentialityHighSC

Subsequent system integrityLowSI

Subsequent system availabilityNoneSA

CVSS vector stringCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N

CVSS communicates standardized severity and impact characteristics. It does not establish whether a system is exploitable in your specific environment.

Record context

CVE Numbering AuthorityVulnCheck

Last updatedNov 8, 2026 14:09:05 UTC

PublishedAug 24, 2026 00:30:48 UTC

ReservedAug 24, 2026 00:15:01 UTC

Credits

Matéo Florian Callec