CVE-2026-128341

ExcelJS through 4.4.0 Denial of Service via Oversized Data Validation sqref

Published Nov 13, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Description

ExcelJS through 4.4.0 contains a resource exhaustion vulnerability in data-validations-xform.js that allows attackers to exhaust CPU and memory by supplying unbounded sqref ranges. Attackers can provide a small crafted workbook with a sqref of A1:XFD1048576 to make xlsx.load() iterate billions of addresses, blocking the event loop and crashing the process with an uncatchable out-of-memory error.

Analysis

No analysis available yet

Affected Products

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

unaffected

Version	Status	Constraints
`0`	affected	≤ 4.4.0

No data.

No data available yet.

Remediation

No remediation available yet

Tracking

Advisories

No advisories available

Metrics

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.

Exploit prediction score: < 1% (0.630% probability within 30 days)

Key SSVC decision points have not yet been added.

References

Link	Providers
https://github.com/exceljs/exceljs
https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/data-validations-xform.js#L216-L227
https://github.com/exceljs/exceljs/issues/3093
https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-f689-fh93-2pm2
https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-data-validation-sqref

History

Nov 13, 2026 9:45 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		ExcelJS through 4.4.0 contains a resource exhaustion vulnerability in data-validations-xform.js that allows attackers to exhaust CPU and memory by supplying unbounded sqref ranges. Attackers can provide a small crafted workbook with a sqref of A1:XFD1048576 to make xlsx.load() iterate billions of addresses, blocking the event loop and crashing the process with an uncatchable out-of-memory error.
Title		ExcelJS through 4.4.0 Denial of Service via Oversized Data Validation sqref
First Time appeared		Exceljs Project Exceljs Project exceljs
Weaknesses		CWE-770
CPEs		cpe:2.3:a:exceljs_project:exceljs::::::::
Vendors & Products		Exceljs Project Exceljs Project exceljs
References		https://github.com/exceljs/exceljs https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xform/sheet/data-validations-xform.js#L216-L227 https://github.com/exceljs/exceljs/issues/3093 https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-f689-fh93-2pm2 https://www.vulncheck.com/advisories/exceljs-through-4.4.0-denial-of-service-via-oversized-data-validation-sqref
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'}`