CVE-2026-128339

ExcelJS through 4.4.0 Memory Exhaustion via Oversized Merged Cell Range

Published Nov 13, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
ExcelJS through 4.4.0 contains a memory exhaustion vulnerability in Worksheet._parseMergeCells that allows attackers to crash applications by supplying unbounded mergeCell ranges. Attackers can craft a small workbook with a mergeCell ref like A1:XFD1048576, causing xlsx.load() to create billions of Row and Cell objects and abort the process.

Analysis

No analysis available yet

Remediation

No remediation available yet

Tracking

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Advisories

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History
Type Values Removed Values Added
Description ExcelJS through 4.4.0 contains a memory exhaustion vulnerability in Worksheet._parseMergeCells that allows attackers to crash applications by supplying unbounded mergeCell ranges. Attackers can craft a small workbook with a mergeCell ref like A1:XFD1048576, causing xlsx.load() to create billions of Row and Cell objects and abort the process.
Title ExcelJS through 4.4.0 Memory Exhaustion via Oversized Merged Cell Range
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
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'}

Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 13, 2026, 9:33 AM
Reserved
Nov 13, 2026, 1:20 AM
Status
Awaiting Analysis
Published
Nov 13, 2026, 10:18 AM
Modified
Nov 13, 2026, 3:48 PM