exceljs through 4.4.0 contains a denial of service vulnerability that allows attackers to block the event loop by supplying unbounded row r attributes parsed in row-xform.js. Attackers can craft an XLSX file with a row numbered far beyond Excel's limit, making getSheetValues(), workbook writes and CSV export consume time proportional to that number.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
exceljs exceljs unaffected
Version Status Constraints
0 affected ≤ 4.4.0

No data.

No data.

No data.

Project Subscriptions

Vendors Products
Exceljs Project Subscribe
Exceljs Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/exceljs/exceljs cve-icon
https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L571-L580 cve-icon
https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/worksheet.js#L886-L893 cve-icon
https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/row-xform.js#L73-L77 cve-icon
https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-3gm5-qxj8-89rr cve-icon
https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-row-number cve-icon
History

Fri, 13 Nov 2026 09:45:00 +0000

Type Values Removed Values Added
Description exceljs through 4.4.0 contains a denial of service vulnerability that allows attackers to block the event loop by supplying unbounded row r attributes parsed in row-xform.js. Attackers can craft an XLSX file with a row numbered far beyond Excel's limit, making getSheetValues(), workbook writes and CSV export consume time proportional to that number.
Title ExcelJS through 4.4.0 Denial of Service via Oversized Row Number
First Time appeared Exceljs Project
Exceljs Project exceljs
Weaknesses CWE-606
CPEs cpe:2.3:a:exceljs_project:exceljs:*:*:*:*:*:*:*:*
Vendors & Products Exceljs Project
Exceljs Project exceljs
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-13T09:33:33.699Z

Reserved: 2026-11-13T01:20:42.132Z

Link: CVE-2026-128343

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses