Vulnerability record/PUBLISHED/Published Nov 13, 2026 09:33:31 UTC

CVE-2026-128347

ExcelJS through 4.4.0 contains an arbitrary file read vulnerability in the streaming WorkbookWriter that allows attackers to read local files by supplying crafted image filenames to addImage. Attackers can inject ../ path segments into user-controlled image paths, causing addMedia to embed any file readable by the Node.js process under xl/media in the generated workbook.

Base score8.7/ 10

SeverityHighCVSS 4.0

Exploitability / impact

CVSS metric breakdown

Vector-derived attributes

Base severityHigh

Attack vectorNetworkAV

Attack complexityLowAC

Attack requirementsNoneAT

Privileges requiredNonePR

User interactionNoneUI

Vulnerable system confidentialityHighVC

Vulnerable system integrityNoneVI

Vulnerable system availabilityNoneVA

Subsequent system confidentialityNoneSC

Subsequent system integrityNoneSI

Subsequent system availabilityNoneSA

CVSS vector stringCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/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 13, 2026 22:31:42 UTC

PublishedNov 13, 2026 09:33:31 UTC

ReservedNov 13, 2026 01:20:43 UTC

Credits

Matéo Florian Callec