Path Traversal Vulnerability in ExcelJS-Hardened Product by GitHub
CVE-2026-78208

8.7HIGH

Key Information:

Vendor

Exceljs

Status
Exceljs
Vendor
CVE Published:
24 August 2026

What is CVE-2026-78208?

The exceljs-hardened library prior to version 5.0.0 is vulnerable to a path traversal issue within the Workbook.addImage() function. This vulnerability allows attackers to manipulate file paths, enabling them to access and embed arbitrary files that are visible to the Node.js process into the generated workbook. This can lead to unauthorized access to sensitive data, highlighting the importance of securing file path validations within applications.

Affected Version(s)

exceljs 0 <= 4.4.0

References

https://github.com/exceljs/exceljs
product
https://github.com/mateocallec/exceljs-hardened/security/...
third-party-advisory
https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/wo...
technical-description

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Matéo Florian Callec
.